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GeometryParallelLines
20161115
www.njctl.org
http://www.njctl.org
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TableofContentsClickonthetopictogotothatsection
Lines:Intersecting,Parallel&Skew
ConstructingParallelLines
Lines&Transversals
ParallelLines&Proofs
PropertiesofParallelLines
PARCCSampleQuestions
4
ConstructionsVideosTableofContentsClickonthetopictogotothatvideo
ParallelLinesCorrespondingAngles
ParallelLinesAlternateInteriorAngles
ParallelLinesAlternateExteriorAngles
ParallelLinesusingMenuOptions
5
Throughoutthisunit,theStandardsforMathematicalPracticeareused.
MP1:Makingsenseofproblems&persevereinsolvingthem.MP2:Reasonabstractly&quantitatively.MP3:Constructviableargumentsandcritiquethereasoningofothers.MP4:Modelwithmathematics.MP5:Useappropriatetoolsstrategically.MP6:Attendtoprecision.MP7:Lookfor&makeuseofstructure.MP8:Lookfor&expressregularityinrepeatedreasoning.
Additionalquestionsareincludedontheslidesusingthe"MathPractice"Pulltabs(e.g.ablankoneisshowntotherightonthisslide)withareferencetothestandardsused.
Ifquestionsalreadyexistonaslide,thenthespecificMPsthatthequestionsaddressarelistedinthePulltab.
MathPractic
e
6
Lines:Intersecting,Parallel&Skew
ReturntoTableofContents
7
Euclid'sFifthPostulate
Euclid'sFifthPostulateisperhapshismostfamous.
It'sbotheredmathematiciansforthousandsofyears.
FifthPostulate:That,ifastraightlinefallingontwostraightlinesmaketheinterioranglesonthesamesidelessthantworightangles,thetwostraightlines,ifproducedindefinitely,meetonthatsideonwhicharetheangleslessthanthetwo
rightangles.
8
Euclid'sFifthPostulate
ThisseemedsonaturalthattheGreekgeometersthoughttheyshouldbeabletoproveit,andwouldn'tneedittobeapostulate.
Theyresistedusingitforyears.
However,theyfoundthattheyneededit.
Andtheycouldn'tproveit.
Theyjusthadtopostulateit.
9
Itsaysthattherearetwopossiblecasesifonelinecrossestwoothers.
Euclid'sFifthPostulate
1 2
3 4
10
Thepairsofanglesonbothsides,(either1&3or2&4)eachaddupto180,tworightangles,andthetworedlinesnevermeet.
Likethis....
Euclid'sFifthPostulate
1 2
3 4
11
Orlikethis.
1 2
3 4
Euclid'sFifthPostulate
Or,...
12
Theyadduptolessthan180ononeside(angles2&4),andmorethan180ontheother(angles1&3),inwhichcasethelinesmeetonthesidewiththesmallerangles.
Likethis...
1 2
3 4
Euclid'sFifthPostulate
13
Orlikethis.
Euclid'sFifthPostulate
1 2
3 4
14
Theycouldn'tprovethisfromtheotheraxiomsandpostulates.But,withoutittherewerealotofimportantpiecesofgeometrythey
couldn'tprove.
SotheygaveinandmadeitthefinalpostulateofEuclideanGeometry.Forthenextthousandsofyears,mathematiciansfeltthesameway.Theykepttryingtoshowwhythispostulatewasnot
needed.
Noonesucceeded.
Euclid'sFifthPostulate
15
In1866,BernhardRiemanntooktheotherperspective.
ForhisdoctoraldissertationhedesignedageometryinwhichEuclid'sFifthPostulatewasnottrue,ratherthanassumingitwas.
ThisledtononEuclideangeometry.Whereparallellinesalwaysmeet,ratherthannevermeet.
Euclid'sFifthPostulate
16
Buthalfacenturylater,nonEuclideangeometry,basedonrejectingthefifthpostulate,becamethemathematicalbasisofEinstein'sGeneralRelativity.
Itcreatestheideaofcurvedspacetime.Thisisnowtheacceptedtheoryfortheshapeofouruniverse.
Euclid'sFifthPostulate
17
Linesthatareinthesameplaneandnevermeetarecalledparallel.
Linesthatintersectarecallednonparallelorintersecting.Alllinesthatintersectareinacommonplane.
Euclid'sFifthPostulate
18
Linesthatareindifferentplanesandnevermeetarecalledskew.
Euclid'sFifthPostulate
m
n
P
Q
Linesm&ninthefigureareskew.
19
B
a
TheParallelPostulate
OnewayofrestatingEuclid'sFifthPostulateistosaythatparallellinesnevermeet.
AnextensionofitistheParallelPostulate:givenalineandapoint,notontheline,thereisone,andonlyone,linethatcanbedrawnthroughthepointwhichisparalleltotheline.
Canyouestimatewhere
theparallellinewouldbe?
MathPractic
e
QuestiononthisslideaddressesMP2
20
B
a
CanyouimagineanyotherlinewhichcouldbedrawnthroughPointBandstillbeparalleltolinea?
TheParallelPostulate
MathPractic
e
QuestiononthisslideaddressesMP2
21
Parallellinesaretwolinesinaplanethatnevermeet.
WewouldsaythatlinesDEandFGareparallel.
Or,symbolically:
Parallel,IntersectingandSkew
DE FG
D E
F G
MathPractic
e
22
Linescannotbeassumedtobeparallelunlessitisindicatedthattheyare.Justlookingliketheyareparallelisnotsufficient.
Therearetwowaysofindicatingthatlinesareparallel.
Thefirstwayisasshownonthepriorslide:
IndicatingLinesareParallel
D E
F G
DE FG
23
IndicatingLinesareParallel
m
k
Theotherwaytoindicatelinesareparallelistolabelthemwitharrows,asshownbelow.
Thelineswhichsharethearrow(showninredtomakeitmorevisiblehere)areparallel.
Iftwodifferentpairsoflinesareparallel,theoneswiththematchingnumberofarrowsareparallel,asshownonthenextslide.
MathPractic
e
24
IndicatingLinesareParallel
m
k
a
b
Thisindicatesthatlineskandmareparalleltoeachother.
And,linesaandbareparalleltoeachother.
Butlineskandmarenotparalleltoaandb.
25
Iftwodifferentlinesinthesameplanearenotparalleltheyareintersecting,andtheyintersectatonepoint.
Wealsoknowthatfouranglesareformed.
Parallel,IntersectingandSkew
D
E
F G
26
Fromthesefourangles,therearefourpairsoflinearanglesthatareformedorlinearpairs.
Linearpairsareadjacentanglesformedbyintersectinglinestheanglesaresupplementary.
1&3areonelinearpair
Parallel,IntersectingandSkew
D
E
F G1 2
3 4
Listtheotherlinearpairs.
Ans
wer
27
Iftheadjacentanglesformedbyintersectinglinesarecongruent,thelinesareperpendicular.
PerpendicularLines
D
E
F G
DE FGSymbolically,thisisstatedas
MathPractic
e
28
Iftwolinesintersect,thentheydefineaplane,soarecoplanar.
SkewLines
m
n Q
PLinesm&ninthefigureareskew.
Twolinesthatdonotintersectcaneitherbeparalleliftheyareinthesameplaneorskewiftheyareindifferentplanes.
MathPractic
e
29
Usingthefollowingdiagram,namealinewhichisskewwithLineHG:alinethatdoesnotlieinacommonplane.
A B
CD
E F
GH
SkewLines
Ans
wer
ThisexampleaddressesMP2
30
1 Arelinesaandbskew?
Yes No
a
b
G Ans
wer Yes,linesaandbareskew.Linesaandbare
noncoplanaranddonotintersect.
31
2 HowmanylinescanbedrawnthroughCandparalleltoLineAB?
B
AC
Ans
wer
32
A B
CD
E F
GH
3 NamealllinesparalleltoEF.
A ABB BCC DCD HDE HG
Ans
wer
33
4 NamelinesskewtoEF.
A BCB DCC HDD ABE GC
A B
CD
E F
GH
Ans
wer
34
5 Twointersectinglinesarealwayscoplanar.
True False
Ans
wer
35
6 Twoskewlinesarecoplanar.
True False
Ans
wer
36
7 Completethisstatementwiththebestappropriateword:
Twoskewlinesare__________parallel.
A alwaysB neverC sometimes
Ans
wer
37
Lines&Transversals
ReturntoTableofContents
38
123 4
56
7 8
k
m
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Transversals
(ThisisthenameofthelinethatEuclidusedtointersecttwolinesinhisfifthpostulate.)
Intheimage,transversal,Linen,isshownintersectingLinekandLinem.
ATransversalisalinethatintersectstwoormorecoplanarlines.
LinekandLinemmayormaynotbeparallel.
39
InteriorAnglesarethe4anglesthatliebetweenthetwolines.
Whenatransversalintersectstwolines,eightanglesareformed.Theseanglesaregivenspecialnames.
3 4
56
k
m
n
AnglesFormedbyaTransversal
40
ExteriorAnglesarethe4anglesthatlieoutsidethetwolines.
Whenatransversalintersectstwolines,eightanglesareformed.Theseanglesaregivenspecialnames.
12
7 8
k
m
n
AnglesFormedbyaTransversal
41
8 Namealloftheinteriorangles.
A 1
B 2
C 3
D 4
E 5
F 6
G 7
H 8
123 4
567 8
k
m
n
Ans
wer
42
9 Namealloftheexteriorangles.
A 1
B 2
C 3
D 4
E 5
F 6
G 7
H 8
123 4
567 8
k
m
n
Ans
wer
43
CorrespondingAnglesarepairsofanglesthatlieinthesamepositionrelativetothetransversal,asshownabove.
CorrespondingAngles
123 4
567 8
k
n
m
Therearefourpairsofcorrespondinganglesformedwhenatransversalintersectstwolines.
44
10 Whichanglecorrespondswith1?
123 4
567 8
k
m
n
Ans
wer
45
11 Whichanglecorrespondswith7?
123 4
567 8
k
m
n
Ans
wer
46
12 Whichanglecorrespondswith6?
123 4
567 8
k
m
n
Ans
wer
47
13 Whichanglecorrespondswith4?
123 4
567 8
k
m
n
Ans
wer
48
Therearetwopairsformedbythetransversaltheyareshownaboveinredandblue.
AlternateInteriorAngles
3 4
56
k
m
n
AlternateInteriorAnglesareinterioranglesthatlieonoppositesidesofthetransversal.
MathPractic
e
MP6Emphasizebreakingapartthewordsineachvocabularytermtounderstandthemeaning.
Alternatemeans"opposite"Interiormeans"inside"
SoAlternateInteriorAnglesareonoppositesidesofthetransversalandinsideoftheother2lines.
49
AlternateExteriorAngles
12
7 8
k
m
n
Therearetwopairsformedbythetransversaltheyareshownaboveinredandblue.
AlternateExteriorAnglesareexterioranglesthatlieonoppositesidesofthetransversal.
MathPractic
e
MP6Emphasizebreakingapartthewordsineachvocabularytermtounderstandthemeaning.
Alternatemeans"opposite"Exteriormeans"outside"
SoAlternateExteriorAnglesareonoppositesidesofthetransversalandoutsideoftheother2lines.
50
14 Whichisthealternateinterioranglethatispairedwith3?
A 1B 2C 3D 4
E 5F 6G 7H 8
123 4
567 8
k
m
n
Ans
wer
51
15 Whichisthealternateexterioranglethatispairedwith7?
123 4
567 8
k
m
nA 1B 2C 3D 4E 5F 6G 7H 8
Ans
wer
52
123 4
567 8
k
m
n
16 Whichisthealternateexterioranglethatispairedwith2?
A 1B 2C 3D 4E 5F 6G 7H 8
Ans
wer
53
123 4
567 8
k
m
n
17 Whichisthealternateinterioranglethatispairedwith6?
A 1B 2C 3D 4E 5F 6G 7H 8
Ans
wer
D
54
SameSideInteriorAngles
Therearetwopairsformedbythetransversaltheyareshownaboveinredandblue.
3 4
56
k
m
n
SameSideInteriorAnglesareinterioranglesthatlieonthesamesideofthetransversal.
MathPractic
e
MP6Emphasizebreakingapartthewordsineachvocabularytermtounderstandthemeaning.
Samesidemeans"onthesameside",Interiormeans"inside"SoSameSideInteriorAngles
areonsamesideofthetransversalandinsideoftheother2lines.Note:a.k.a.
ConsecutiveInteriorAngles
55
SameSideExteriorAngles
Therearetwopairsformedbythetransversaltheyareshownaboveinredandblue.
12
7 8
k
m
n
SameSideExteriorAnglesareexterioranglesthatlieonthesamesideofthetransversal.
MathPractic
e
56
123 4
567 8
k
m
n
18 Whichisthesamesideinterioranglethatispairedwith6?
A 1B 2C 3D 4E 6F 7G 8
Ans
wer
C
57
123 4
567 8
k
m
n
19 Whichisthesamesideexterioranglethatispairedwith7?
A 1B 2C 3D 4E 6F 7G 8
Ans
wer
B
58
123 4
567 8
k
m
n
a.1and2
b.1and3
c.1and5
d.3and6
e.3and5
f.2and8
Slideeachwordintotheappropriatesquaretoclassifyeachpairofangles.
ClassifyingAngles
AlternateExteriorSameSideInteriorVertical
CorrespondingSameSideExterior AlternateInteriorLinearPair
Ans
wer
59
1 23 4
5 67 8
kj
t
20 3and6are...
A CorrespondingAnglesB AlternateExteriorAnglesC SameSideExteriorAnglesD VerticalAnglesE Noneofthese
Ans
wer
B
60
1 23 4
5 67 8
kj
t
21 1and6are____.
A CorrespondingAnglesB AlternateExteriorAnglesC SameSideExteriorAnglesD VerticalAnglesE Noneofthese
Ans
wer
C
61
1 23 4
5 67 8
kj
t
22 2and7are____.
A CorrespondingAnglesB AlternateInteriorAnglesC SameSideInteriorAnglesD VerticalAnglesE Noneofthese An
swer
B
62
1 23 4
5 67 8
kj
t
23 4and8are____.
A CorrespondingAnglesB AlternateExteriorAnglesC SameSideExteriorAnglesD VerticalAnglesE Noneofthese
Ans
wer
A
63
1 23 4
5 67 8
kj
t
24 1and7are____.A CorrespondingAnglesB AlternateExteriorAnglesC SameSideExteriorAnglesD VerticalAnglesE Noneofthese
Ans
wer E
Theseangleshavenorelationshipw/oneanother
64
1 23 4
5 67 8
kj
t
25 5and8are____.
A CorrespondingAnglesB AlternateExteriorAnglesC SameSideExteriorAnglesD VerticalAnglesE Noneofthese
Ans
wer
D
65
1 23 4
5 67 8
kj
t
26 2and5are____.
A CorrespondingAnglesB AlternateInteriorAnglesC SameSideInteriorAnglesD VerticalAnglesE Noneofthese
Ans
wer
C
66
ParallelLines&Proofs
ReturntoTableofContents
Lab:StartingaBusinessWorksheet
Lab:StartingaBusinessTeacherSlides
MathPractic
e
ThislabaddressesMP1,MP3,MP4,MP6&MP7
http://www.njctl.org/courses/math/geometry/parallel-lines/starting-a-business-lab-2/http://www.njctl.org/courses/math/geometry/parallel-lines/starting-a-business-lab-slides-2/
67
Inadditiontothepostulatesandtheoremsusedsofar,therearethreeessentialpropertiesofcongruenceuponwhichwe
willrelyasweproceed.
Therearealsofourpropertiesofequality,threeofwhicharecloselyrelatedtomatchingpropertiesofcongruence.
PropertiesofCongruenceandEquality
68
TheyallrepresentthesortofcommonsensethatEuclidwouldhavedescribedasaCommonUnderstanding,andwhichwe
wouldnowcallanAxiom.
Thecongruencepropertiesaretrueforallcongruentthings:linesegments,anglesandfigures.
Theequalitypropertiesaretrueforallmeasuresofthingsincludinglengthsoflinesandmeasuresofangles.
PropertiesofCongruenceandEquality
69
Athingisalwayscongruenttoitself.
Whilethisisobvious,itwillbeusedinprovingtheoremsasareason.
Forinstance,whenalinesegmentservesasasideintwodifferenttriangles,youcanstatethatthesidesofthosetrianglesarecongruentwiththereason:
ReflexivePropertyofCongruence
ReflexivePropertyofCongruence
A B
CD
Inthediagram,ACAC
70
Themeasuresofanglesorlengthsofsidescanbetakentobeequaltothemselves,eveniftheyarepartsof
differentfigures,
withthereason:
ReflexivePropertyofEquality
ReflexivePropertyofEquality
A B DC
TheLineSegmentAdditionPostulatetellusthat
AC=AB+BCandBD=CD+BC
TheReflexivePropertyofEqualityindicatesthatthelengthBCisequaltoitselfinbothequations
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SymmetricPropertyofCongruence
Ifonethingiscongruenttoanother,thesecondthingisalsocongruenttothefirst.
Again,thisisobviousbutallowsyoutoreversetheorderofthestatementsaboutcongruentpropertieswiththereason:
SymmetricPropertyofCongruence
Forexample:
ABCiscongruentto DEFthat DEFiscongruentto ABC,
72
SymmetricPropertyofEquality
Ifonethingisequaltoanother,thesecondthingisalsoequaltothefirst.
Again,thisisobviousbutallowsyoutoreversetheorderofthestatementsaboutequalpropertieswiththereason:
SymmetricPropertyofEquality
Forexample:
Ifm ABC=m DEF,thenm DEF=m ABC,
73
Iftwothingsarecongruenttoathirdthing,thentheyarealsocongruenttoeachother.
So,ifABCiscongruenttoDEFandLMNisalsocongruenttoDEF,thenwecansaythatABCiscongruenttoLMNduetothe
Withthereason:
TransitivePropertyofCongruence
TransitivePropertyofCongruence
74
Iftwothingsareequaltoathirdthing,thentheyarealsoequaltoeachother.
IfmA=mBandmC=mB,thenmA=mC
Thisisidenticaltothetransitivepropertyofcongruenceexceptitdealswiththemeasureofthingsratherthanthethings.
TransitivePropertyofEquality
TransitivePropertyofEquality
75
Ifonethingisequaltoanother,thenonecanbesubstitutedforanother.
Thisisacommonstepinaproofwhereonethingisprovenequaltoanotherandreplacesthatotherinanexpressionusingthereason:
SubstitutionPropertyofEquality
Forinstanceifx+y=12,andx=2y
Wecansubstitute2yforxtoget
2y+y=12
andusethedivisionpropertytogety=4
SubstitutionPropertyofEquality
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CorrespondingAnglesTheorem
AccordingtotheCorrespondingAngleswhichoftheaboveanglesarecongruent?
Ifparallellinesarecutbyatransversal,thenthecorrespondinganglesarecongruent.
Ans
wer
AccordingtoCorrespondingAnglesPostulatethefollowinganglesare
congruent:
15263748
77
Wecouldpickanypairofcorrespondingangles:2&63&71&5or4&8.
Together,let'sprovethat2&6arecongruent.
CorrespondingAnglesProof
Tokeeptheargumentclear,let'sjustproveonepairofthoseanglesequalhere.Youcanfollowthesameapproachtoprovetheotherthreepairsofanglesequal.
123 4
567 8
k
m
n
78
Given:LinemandLinekareparallelandintersectedbylinen
Prove:m2=m6
CorrespondingAnglesProof
123 4
567 8
k
m
n
79
Statement1LinemandLinekareparallelandintersectedbylinen
Reason1Given
CorrespondingAnglesProof
123 4
567 8
k
m
nGiven:LinemandLinekareparallelandintersectedbylinen
Prove:m2=m6
MathPractic
e
MP7Emphasizethatthe1ststeptoanyproofisstatingthe"Givens".Then,oneusesthepropertiesofthe1st
statementtoaskquestionsandcontinuetosolvethe
proof.
80
FifthPostulate:That,ifastraightlinefallingontwostraightlinesmaketheinterioranglesonthesamesidelessthantworightangles,thetwostraightlines,ifproducedindefinitely,meetonthatsideofwhicharetheangleslessthanthetworightangles.
RememberEuclid'sFifthPostulate.Theonethatnoonelikesbutwhichtheyneed.Thisiswhereit'sneeded.
Euclid'sFifthPostulate
CorrespondingAnglesProof
123 4
567 8
k
m
nGiven:LinemandLinekareparallelandintersectedbylinen
Prove:m2=m6
81
Euclid'sFifthPostulate
1 2
3 4
Recallthatwelearnedearlyinthisunitthatthismeansthat...
Ifthepairsofinterioranglesonbothsidesofthetransversal,(both1&3or2&4)eachaddupto180,thetworedlinesareparallel...andnevermeet.
82
123 4
567 8
k
m
n
27 So,inthiscase,whichanglesmustaddupto180basedonEuclid'sFifthPostulate?
A 1&4
B 6&8
C 4&5
D 3&6
E Alloftheabove
Ans
wer
C&D
83
Reason2Euclid'sFifthPostulate
Statement2m3+m6=180m4+m5=180
Whenanglessumto180,whattypeofanglesarethey?
CorrespondingAnglesProof
123 4
567 8
k
m
n
Given:LinemandLinekareparallelandintersectedbylinen
Prove:m2=m6
MathPractic
e
QuestionsonthisslideaddressMP2&MP3.
84
Reason3DefinitionofSupplementaryAngles
Statement33&6aresupplementary4&5aresupplementary
Whichotherangleissupplementaryto3,becausetogethertheyformastraightangle?Howabouttoangle6?
CorrespondingAnglesProof
123 4
567 8
k
m
n
Given:LinemandLinekareparallelandintersectedbylinen
Prove:m2=m6
MathPractic
e
QuestionsonthisslideaddressMP2&MP3.
85
Reason4Anglesthatformalinearpairaresupplementary
Statement42&3aresupplementary
Whatdoweknowaboutangleswhohavethesamesupplements?
CorrespondingAnglesProof
123 4
567 8
k
m
n
Given:LinemandLinekareparallelandintersectedbylinen
Prove:m2=m6
MathPractic
e
QuestionsonthisslideaddressMP2&MP4.
86
Reason5Twoanglessupplementarytothesameangleareequal
Statement5m2=m6
CorrespondingAnglesProof
123 4
567 8
k
m
n
Given:LinemandLinekareparallelandintersectedbylinen
Prove:m2=m6
87
Statement Reason
1 LinemandLinekareparallelandintersectedbyLinen Given
2 m4+m5=180m3+m6=180
Euclid'sFifthPostulate
3 4&5aresupplementary3&6aresupplementaryDefinitionofsupplementaryangles
4 3&2aresupplementary Anglesthatformalinearpairaresupplementary
5 m2=m6Twoanglessupplementarytothesameangleareequal
CorrespondingAnglesProofGiven:LinemandLinekareparallelandintersectedbyLinen
Prove:m2=m6
123 4
567 8
k
m
n
88
PropertiesofParallelLines
Thisisanimportantresult,whichwasonlymadepossiblebyEuclid'sFifthPostulate.
Itleadstosomeotherprettyimportantresults.Itallowsustoprovesomepairsofanglescongruentandsomeotherpairsofanglessupplementary.
And,itworksinreverse,ifanyoftheseconditionsaremetwecanprovethatlinesareparallel.
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567 8
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89
ConversesofParallelLineProofs
Weprovedthatiftwolinesareparallel,theircorrespondinganglesareequal.
Theconversemustalsobetrue:
Iftwolinesarecutbyatransversalandthecorrespondinganglesarecongruent,thenthelinesareparallel. Te
ache
rNotes
Youmightneedtoexplainthedifferencebetweenanoriginalifthenstatementanditsconverse,whichisformedbyswitchingthehypothesis&conclusion.Ex:Original:Ifitis3pminNewJersey,thenitis1pminColorado.Converse:Ifitis1pminColorado,thenitis3pminNewJersey.
90
ConversesofParallelLineProofs
Thesamereason:CorrespondingAnglesofParallelLinesareEqualisusedineachcase.
Toprovetherelationshipbetweencertainanglesifweknowthelinesareparallel
OR
Toprovethatthelinesareparallelifweknowtherelationshipbetweenthoseangles.
91
ConversesofParallelLineProofs
Thispatternwillbetrueofeachtheoremweproveabouttheanglesformedbythetransversalintersectingtheparallellines.
Theyprovetherelationshipbetweenanglesoflinesknowntobeparallel,ortheyprovethatthelinesareparallel.
92
123 4
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n
AlternateInteriorAnglesTheorem
AccordingtotheAlternateInteriorAnglesTheoremwhichoftheseanglesarecongruent?
Ifparallellinesarecutbyatransversal,thenthealternateinterioranglesarecongruent.
Ans
wer
93
Given:LinemandLinekareparallelandintersectedbylinen
Prove:35and46
AlternateInteriorAnglesProof
123 4
567 8
k
m
n
94
Statement1LinemandLinekareparallelandintersectedbylinen
Reason1Given
AlternateInteriorAnglesProof
AccordingtotheCorrespondingAnglesTheoremwhichoftheaboveanglesarecongruent?
123 4
567 8
k
m
n
Given:LinemandLinekareparallelandintersectedbylinen
Prove:35and46
MathPractic
e
QuestiononthisslideaddressesMP3&MP6.
95
Reason2Whentwoparallellinesarecutbyatransversal,thecorrespondinganglesarecongruent.
Statement21526
Whichotherangleiscongruentto1?Whichotherangleiscongruentto2?Whyaretheseanglescongruent?
AlternateInteriorAnglesProof
123 4
567 8
k
m
nGiven:LinemandLinekareparallelandintersectedbylinen
Prove:35and46
MathPractic
e
QuestionsonthisslideaddressMP3,MP6&MP7.
96
Reason3Verticalanglesarecongruent.
Whatdoweknowaboutanglesthatarecongruenttothesameangle?Explainyouranswer.
AlternateInteriorAnglesProof
Statement31324
123 4
567 8
k
m
n
Given:LinemandLinekareparallelandintersectedbylinen
Prove:35and46
MathPractic
e
QuestionsonthisslideaddressMP2,MP3&MP6.
97
Reason4Transitivepropertyofcongruence
Statement4 3 5 4 6
Butthosearethepairsofalternateinteriorangleswhichwesetouttoprovearecongruent.So,ourproofiscomplete:AlternateInteriorAnglesofParallelLinesareCongruent
AlternateInteriorAnglesProof
123 4
567 8
k
m
n
Given:LinemandLinekareparallelandintersectedbylinen
Prove:35and46
98
Statement Reason
1 LinemandLinekareparallelandintersectedbyLinen Given
2 15and26Iftwoparallellinesarecutbyatransversal,thenthecorrespondinganglesare
3 13and24 VerticalAnglesare
4 35and46TransitivePropertyofCongruence
AlternateInteriorAnglesProofGiven:LinemandLinekareparallelandintersectedbyLinen
Prove:3546
123 4
567 8
k
m
n
99
ConverseofAlternateInteriorAnglesTheorem
Iftwolinesarecutbyatransversalandthealternateinterioranglesarecongruent,thenthelinesareparallel.
100
123 4
567 8
k
m
n
AlternateExteriorAnglesTheorem
Iftwoparallellinesarecutbyatransversal,thenthealternateexterioranglesarecongruent.
AccordingtotheAlternateExteriorAnglesTheoremwhichanglesarecongruent?
Ans
wer
AccordingtoAlternateExteriorAnglesTheoremthe
followinganglesarecongruent:
1728
101
AlternateExteriorAnglesTheorem
SincetheprooffortheAlternateExteriorAnglesTheoremisverysimilartotheAlternateInteriorAnglesTheorem,youwillbecompletingthisproofasapartofyourHomeworkforthislesson.
102
ConverseofAlternateExteriorAnglesTheorem
Iftwolinesarecutbyatransversalandthealternateexterioranglesarecongruent,thenthelinesareparallel.
103
123 4
567 8
k
m
n
SameSideInteriorAnglesTheorem
Iftwoparallellinesarecutbyatransversal,thenthesamesideinterioranglesaresupplementary.
AccordingtotheSameSideInteriorAnglesTheoremwhichpairsofanglesaresupplementary?
Answ
er
Ans
wer
AccordingtoSameSideInteriorAnglesTheoremthe
followinganglesaresupplementary:
m3+m6=180m4+m5=180
104
SameSideInteriorAnglesProof
Given:Linesmandkareparallelandintersectedbylinen
Prove:3&6aresupplementaryand4&5aresupplementary
123 4
567 8
k
m
n
105
28 Whichreasonappliestostep1?
Statement Reason
1 Linesmandkareparallelandintersectedbylinen ?
2 m3+m6=180m4+m5=180 ?
3 ? Definitionofsupplementarys
123 4
567 8
k
m
nA DefinitionofsupplementaryB Euclid'sFifthPostulateC GivenD AlternateInterior sareE Corresponding sare A
nswer
C
106
29 Whichreasonappliestostep2?
A DefinitionofsupplementaryB Euclid'sFifthPostulateC GivenD AlternateInterior sareE Corresponding sare
Statement Reason
1 Linesmandkareparallelandintersectedbylinen ?
2 m3+m6=180m4+m5=180 ?
3 ? Definitionofsupplementarys
123 4
567 8
k
m
n
Ans
wer
107
30 Whichstatementshouldbeinstep3?
A B C D E
Statement Reason
1 LinemandLinekareparallelandintersectedbyLinen ?
2 Thesumsofm3andm6andofm4andm5are180. ?
3 ?Definitionofsupplementary
angles
123 4
567 8
k
n
m
3and6aresupplementary6and5aresupplementary2and6aresupplementary4and5aresupplementary3and5aresupplementary A
nswer
108
Statement Reason
1 Linesmandkareparallelandintersectedbylinen Given
2 m3+m6=180m4+m5=180 Euclid'sFifthPostulate
3 3and6aresupplementary4and5aresupplementary Definitionofsupplementarys
SameSideInteriorAnglesProof
Given:LinemandLinekareparallelandintersectedbyLinen
Prove:3&6aresupplementaryand4&5aresupplementary
123 4
567 8
k
m
n
109
ConverseofSameSideInteriorAnglesTheorem
Iftwolinesarecutbyatransversalandthesamesideinterioranglesaresupplementary,thenthelinesareparallel.
110
123 4
567 8
k
m
n
SameSideExteriorAnglesTheoremIftwoparallellinesarecutbyatransversal,thenthesamesideexterioranglesaresupplementary.
AccordingtotheSameSideExteriorAnglesTheoremwhichanglesaresupplementary?
Ans
wer
AccordingtoSameSideExteriorAnglesTheoremthefollowinganglesare
supplementary:
m2+m7=180m1+m8=180
111
SameSideExteriorAnglesProof
Given:LinesmandkareparallelandintersectedbyLinen
Prove:2&7aresupplementary
Inprovingthat2&7aresupplementarywearetherebyprovingthat1&8aresupplementaryasthesameargumentsapplytobothpairsofangles.
123 4
567 8
k
m
n
112
31 Whichreasonappliestostep1?A Definitionofsupplementary sB SubstitutionpropertyofequalityC GivenD sthatformalinearpairaresupplementary
Statement Reason
1 LinemandLinekareparallelandintersectedbyLinen ?
2 ? Samesideinterioranglesaresupplementary
3 ? Anglesthatformalinearpairaresupplementary4 26and37 ?5 2&7aresupplementary ?
E ssupplementarytothesame are
123 4
567 8
k
m
n
Ans
wer
C
113
Statement Reason
1 LinemandLinekareparallelandintersectedbyLinen ?
2 ? Samesideinterioranglesaresupplementary
3 ? Anglesthatformalinearpairaresupplementary4 26and37 ?5 2&7aresupplementary ?
32 Whichstatementismadeinstep2?
A 2&1aresupplementaryB 7&8aresupplementaryC 3&6aresupplementaryD 4&5aresupplementaryE 5&8aresupplementary
123 4
567 8
k
m
n
Ans
wer
114
33 Whichstatementismadeinstep3?A B C D E
2&3aresupplementary1&3aresupplementary6&8aresupplementary6&7aresupplementary7&1aresupplementary
Statement Reason
1 LinemandLinekareparallelandintersectedbyLinen ?
2 ? Samesideinterioranglesaresupplementary
3 ? Anglesthatformalinearpairaresupplementary4 26and37 ?5 2&7aresupplementary ?
123 4
567 8
k
m
n
Ans
wer
115
Statement Reason
1 LinemandLinekareparallelandintersectedbyLinen ?
2 ? Samesideinterioranglesaresupplementary
3 ? Anglesthatformalinearpairaresupplementary4 26and37 ?5 2&7aresupplementary ?
34 Whichreasonappliestostep4?A Definitionofsupplementary sB SubstitutionpropertyofequalityC GivenD sthatformalinearpairaresupplementary
E ssupplementarytothesame are
123 4
567 8
k
m
n
Ans
wer
116
35 Whichreasonappliestostep5?
Statement Reason
1 Linesmandkareparallelandintersectedbylinen ?
2 ? Samesideinterioranglesaresupplementary
3 ? Anglesthatformalinearpairaresupplementary4 26and37 ?
5 2&7aresupplementary ?
A DefinitionofsupplementarysB SubstitutionpropertyofequalityC GivenD Anglesthatformalinearpairaresupplementary
E ssupplementarytothesameare
123 4
567 8
k
m
n
Ans
wer
117
SameSideExteriorAnglesProof
Statement Reason
1 Linesmandkareparallelandintersectedbylinen Given
2 3&6aresupplementary Samesideinterioranglesaresupplementary
3 2&3aresupplementary6&7aresupplementaryAnglesthatformalinearpairaresupplementary
5 26and37Anglessupplementarytothesameanglearecongruent
6 2&7aresupplementary SubstitutionPropertyofEquality
Given:LinemandLinekareparallelandintersectedbyLinen
Prove:2&7aresupplementary(andtherebythat1&8areaswell)
123 4
567 8
k
m
n
118
ConverseofSameSideExteriorAnglesTheorem
Iftwolinesarecutbyatransversalandthesamesideexterioranglesaresupplementary,thenthelinesareparallel.
119
PropertiesofParallelLines
ReturntoTableofContents
120
PropertiesofParallelLines
Thereareseveraltheoremsandpostulatesrelatedtoparallellines.Atthistime,pleasegotothelabtitled,"PropertiesofParallelLines".
Clickheretogotothelabtitled,"PropertiesofParallelLines"
MathPractic
e
ThislabaddressesMP1,MP3,MP4,MP5,MP6,MP7&MP8
https://njctl.org/courses/math/geometry/parallel-lines/attachments/properties-of-parallel-lines-2/https://njctl.org/courses/math/geometry/parallel-lines/properties-of-parallel-lines/
121
PropertiesofParallelLines
123 4
567 8
k
n km
m
Example:Ifm4=54,findthem8.
Explainyouranswer.
Ans
wer
AccordingtoCorrespondingAnglesPostulate48,therefore
m8=54.
ThisexampleaddressesMP1,MP2&MP3
122
PropertiesofParallelLines
Example:Ifm3=125,findthem5.
Explainyouranswer.
123 4
567 8
k
n km
m
Ans
wer
ThisexampleaddressesMP1,MP2&MP3
123
PropertiesofParallelLines
Example:Ifm2=78,findthem8.
Explainyouranswer.
123 4
567 8
k
m
n km
Ans
wer
ThisexampleaddressesMP1,MP2&MP3
124
PropertiesofParallelLines
Example:Ifm3=163,findm6.Explainyouranswer.
123 4
567 8
k
m
n km
Ans
wer
ThisexampleaddressesMP1,MP2&MP3
125
PropertiesofParallelLines
Namealloftheanglescongruentto1.
123 4
567 8
k
m
n km
Ans
wer
1357
126
PropertiesofParallelLines
Namealloftheanglessupplementaryto1.
123 4
567 8
k
m
n km
Ans
wer
1issupplementarytoangles:2,4,6,and8.
127
36 Findalloftheanglescongruentto5.A 1B 4C 8D alloftheabove
1 23 4
5 687
jm
j
m
k
Ans
wer
D
128
37 Findthevalueofx.
j
m(5x+30)
120
jm
k
Ans
wer
129
38 Findthevalueofx.
j
m(1.5x+40)
110
jmk
Ans
wer
130
39 Ifthem4=116thenm9=_____?
kmnp
n p
2 13 4
567 8
91011 12
131415 16
k
m
Ans
wer
64
131
40 Ifthem15=57,thenthem2=_____.
A 57B 123C 33D noneoftheabove
kmnp
n p
2 13 4
567 8
91011 12
131415 16
k
m
Ans
wer
132
Withthegivendiagram,notransversalexistsbutwecanextendoneofthelinestomakeatransversal.
ExtendingLinestoMakeTransversals
131
1
41
Findm1.
133
Thenfillintheanglewhichiscorrespondingtothe131angle.Whichanglecorrespondstothe131?
ExtendingLinestoMakeTransversals
131
1
41
Findm1.
Ans
wer
ThequestiononthisslideaddressesMP7.
Thetopangleinthesetof4anglesinthefigure(ontherightsideofthefigure).
134
Thenfindthemeasurementoftheangleadjacentto131thatisinsideofthetriangle.Whatisthemeasurementofthisangle?Explainyouranswer.
ExtendingLinestoMakeTransversals
131
1
41
131
Findm1.
Ans
wer
ThequestionsonthisslideaddressMP2&MP3.
49degreesTheanglesarealinearpair,
whichmakesthemsupplementary.
135
Asyoumayrecall,thethirdangleinthetrianglemustmakethesumoftheanglesequalto180.Whatisthemeasurementofthe3rdangleinthetriangle?
ExtendingLinestoMakeTransversals
131
1
41
13149
Findm1.
Ans
wer
ThequestiononthisslideaddressesMP2.
136
And,finallythatangle1issupplementarytothat90angle.Whatism1?
ExtendingLinestoMakeTransversals
131
1
41
13149
90
Findm1.
MathPractic
e
ThequestiononthisslideaddressesMP2.
137
m1=90
ExtendingLinestoMakeTransversals
131
1
41
13149
90
Findm1.
138
Findthevaluesofxandy.
DoubleTransversals
132
x
(4y+12)
Ans
wer
AdditionalQ'sthataddressMP's:Whatinformationareyougiven?(MP1)Whatdoyouneedtofind?(MP1)Createanequationtorepresenttheproblem.(MP2)Howaretheanglesw/theexpressionsrelatedthe132angle?(MP7)
139
(14x+6) 66
2z
(3y6)
Findthevaluesofx,y,andz.
TransversalsandPerpendicularLines
Ans
wer
140
41 Findthem1.
1
126
110
Ans
wer
141
42 Findthevalueofx.
(3x)
54
A 12B 54C 42D 18
Ans
wer
142
43 Findthevalueofx.
(2x3)
(4x61) Ans
wer
143
122
(16x+10)
44 Findthevalueofx.
Ans
wer
144
Ifm3=56,findthem7thatmakeslineskandmparallel.
Explainyouranswer.
123 4
567 8
k
m
n
ProvingLinesareParallel
Ans
wer
AccordingtotheConverseoftheCorresponding
AnglesTheorem,ifm3=m7,thenkm.
Therefore,ifm3=56,thenm7=56.
ThisexampleaddressesMP1,MP2&MP3
145
Ifm4=110,findthem6thatmakeslineskandmparallel.
Explainyouranswer.
ProvingLinesareParallel
Ans
wer
AccordingtotheConverseoftheAlternateInteriorAnglesTheorem,ifm4=
m6,thenkm.Therefore,ifm4=110,thenm6=110.
ThisexampleaddressesMP1,MP2&MP3
123 4
567 8
k
m
n
146
Ifm1=48,findthem7thatmakeslineskandmparallel.
Explainyouranswer.
ProvingLinesareParallel
Ans
wer
AccordingtotheConverseoftheAlternateExteriorAnglesTheorem,ifm1=m7,thenkm.Ifm1=48,
thenm7=48
ThisexampleaddressesMP1,MP2&MP3
123 4
567 8
k
m
n
147
Ifm5=54,findthem4thatmakeslineskandmparallel.
Explainyouranswer.
ProvingLinesareParallel
123 4
567 8
k
m
n
Ans
wer
AccordingtotheConverseoftheSameSideAnglesTheorem,ifm5+m4=
180,thenkm.Therefore,ifm5=54,thenm4=126 .
ThisexampleaddressesMP1,MP2&MP3
148
45 Whichstatementwouldshowlineskandmparallel?
123 4
567 8
k
m
n
A m2=m4B m5+m6=180
C m3=m5D m1+m5=90
Ans
wer
149
46 Inthisdiagram,whichofthefollowingistrue?
12364 57
132
e f g
h
i
A efB fgC hiD eg
Ans
wer
D
150
47 IflinesaandbarecutbyatransversalwhichofthefollowingwouldNOTprovethattheyareparallel?
A Correspondinganglesarecongruent.B Alternatneinterioranglesarecongruent.C Samesideinterioranglesarecomplementary.D Samesideinterioranglesaresupplementary.E Alloftheabove. An
swer
C
151
48 Findthevalueofxforwhichab.
a
bx
115
d
Ans
wer
152
49 Findthevalueofxwhichmakesab.
(6x20)
2x
a
b
cd
Ans
wer
x=25
153
50 Findthevalueofxforwhichmn.
m
n
(14x10)
(5x) Answ
er
10
154
51 Ifab,howcanweprovem1=m4?
A CorrespondinganglestheoremB ConverseofcorrespondinganglestheoremC AlternateInterioranglestheoremD Converseofalternateinterioranglestheorem
a b
c1 4
32
Ans
wer
C
155
52 Ifm1=m3,howcanweproveab?
A CorrespondinganglestheoremB ConverseofcorrespondinganglestheoremC AlternateInterioranglestheoremD Converseofalternateinterioranglestheorem
a b
c1 4
32
Ans
wer
156
53 Givenm1=m2,m3=m4,whatcanweprove?(chooseallthatapply)
A abB cdC lineaisperpendiculartolinecD linebisperpendiculartolined
ab
d
12
3
4 5 c
Ans
wer
157
54 Givenab,whatcanweprove?
A m1=m2B m1=m4C m2=m3D m1+m3=180
a b
c1 4
32
Ans
wer
158
ConstructingParallelLines
ReturntoTableofContents
MathPractic
e
Thisentirelessonw/constructionsaddressesMP5
159
ParallelLineConstruction
Constructinggeometricfiguresmeansyouareconstructinglines,angles,andfigureswithbasictoolsaccurately.
Weuseacompass,andstraightedgeforconstructions,butwealsousesomepaperfoldingtechniques.
Clickheretoseeananimatedconstructionofaparallellinethrough
apoint.
Constructionby:MathIsFun
http://www.mathsisfun.com/geometry/construct-paranotline.html
160
Given:LineABandpointC,notontheline,drawasecondlinethatisparalleltoABandgoesthroughpointC.
Therearethreedifferentmethodstoachievethis.
Method1:CorrespondingAngles
ParallelLineConstruction
A
C
B
161
Thetheoryofthisconstructionisthatthecorrespondinganglesformedbyatransversalandparallellinesareequal.
Tousethistheory,wewilldrawatransversalthroughCthatcreatesanacuteanglewithlineAB.
ThenwewillcreateacongruentangleatC,onthesamesideofthetransversalastheacuteangleformedwithlineAB.
Sincethesearecongruentcorrespondingangles,thelinesareparallel.
A
C
B
ParallelLineConstruction:Method1
162
Step1:DrawatransversaltoABthroughpointCthatintersectsABatpointD.AnacuteanglewithpointDasavertexisformed(themeasureoftheangleisnotimportant).
ParallelLineConstruction:Method1
A
C
BD
TheangleCDBistheanglewewillreplicateatpointConthesamesideofthetransversal.
163
A
C
BD
F
E
Step2:CenterthecompassatpointDanddrawanarcthatintersectsbothlines.Usingthesameradiusofthecompass,centeritatpointCanddrawanotherarc.LabelthepointofintersectiononthesecondarcF.
0135Wearefollowingthe
procedureweusedpreviouslytoconstructacongruentangle.
ThisstepistomarkthesamedistancesfromDandfromC.
ParallelLineConstruction:Method1
164
Step3:Setthecompassradiustothedistancebetweenthetwointersectionpointsofthefirstarc.
A
C
BD
F
0
118
Thisreplicatesthedistancebetweenwherethearcintersectsthetwolegsoftheangleatthesamedistancefromthevertex.
WhenthatisreplicatedatCtheangleconstructedwillbecongruentwiththeoriginalangle.
ParallelLineConstruction:Method1
165
Step4:CenterthecompassatthepointFwherethesecondarcintersectslineDCanddrawathirdarc.
A
C
BD
F
0
118
ParallelLineConstruction:Method1
Thisassuresthatthearclengthforeachangleisidentical.
166
Step5:MarkthearcintersectionpointEanduseastraightedgetojoinCandE.
A
C
BD
F
E
ParallelLineConstruction:Method1
CDB FCEthereforeABCE
167
Herearemyparallellineswithouttheconstructionlines.
A BD
C E
ParallelLineConstruction:Method1
168
VideoDemonstratingConstructingParallelLineswithCorrespondingAngles
usingDynamicGeometricSoftware
Clickheretoseevideo
http://youtu.be/OZwIX9kVp0M
169
Thetheoryofthisconstructionisthatthealternateinterioranglesformedbyatransversalandparallellinesareequal.
Tousethistheory,wewilldrawatransversalthroughCthatcreatesanacuteanglewithlineAB.
ThenwewillcreateacongruentangleatC,ontheoppositesideofthetransversalastheacuteangleformedwithlineAB.
Sincethesearecongruentalternateinterioranglesthelinesareparallel.
A
C
B
ParallelLineConstruction:Method2
170
A B
C
Method2:AlternateInteriorAnglesGivenABandpointC,notontheline,drawasecondlinethatisparalleltoABandgoesthroughpointC.
171
A B
C
D
Method2:AlternateInteriorAnglesStep1:DrawatransversaltolineABthroughpointCthatintersectslineABatpointD.AnacuteanglewithpointDasavertexisformed.
TheangleCDBistheanglewewillreplicateatpointContheoppositesideofthetransversal.
172
A B
C
D
F
E
Method2:AlternateInteriorAngles
0 148
Step2:CenterthecompassatpointDanddrawanarcthatintersectsbothlines,atpointsEandatF.Wearefollowingtheprocedureweusedpreviouslytoconstructacongruentangle.
ThisstepistomarkthesamedistancefromDonbothlines.
173
A B
C
D
F
E
G
Method2:AlternateInteriorAngles
0144
Step3:Usingthesameradius,centerthecompassatpointCanddrawanarcthatpassesthroughlineDCatpointG.
ThisreplicatesthesamedistancealongthetransversalandthenewlinethatwillbedrawnfromCaswasdoneforthedistancesfromD.
174
A B
C
D
F
E
G
H
Method2:AlternateInteriorAnglesStep4:Again,withthesameradius,centerthecompassatpointGanddrawathirdarcwhichintersectstheearlierone,atH.
0
144
Thisnowfindsthatsamedistancefromwherethearcintersectsthetransversalandthenewlineaswasthecaseforthetransversalandtheoriginalline.
175
A B
C
D
F
E
G
H
Step5:DrawlineCH,whichwillbeparalleltolineABsincetheiralternateinterioranglesarecongruent.
Method2:AlternateInteriorAngles
0
144
SinceanglesHCGandBDFarecongruentandarealternateinteriorangles,thelinesareparallel.
176
A B
C
D
H
Herearethelineswithouttheconstructionstepsshown.
Method2:AlternateInteriorAngles
177
VideoDemonstratingConstructingParallelLineswithAlternateInteriorAngles
usingDynamicGeometricSoftware
Clickheretoseevideo
http://youtu.be/p2iPjRX3LOM
178
A B
C
Method3:AlternateExteriorAnglesGivenlineABandpointC,notontheline,drawasecondlinethatisparalleltolineABandgoesthroughpointC.
179
B
C
DA
Method3:AlternateExteriorAnglesStep1:DrawatransversaltolineABthroughpointCthatintersectslineABatpointD.AnacuteanglewithpointDasavertexisformed.
180
A B
C
D
E
Method3:AlternateExteriorAnglesStep2:CenterthecompassatpointDanddrawanarctointersectlinesABandDContheoppositesideofpointCatAandE. 0
168
181
A B
C
D
F
E
Method3:AlternateExteriorAnglesStep3:KeepingtheradiusthesamedrawanarccenteredonCthatintersectslineDCaboveC,atF.
0
168
182
A B
C
D
F
E
G
Method3:AlternateExteriorAnglesStep4:StillkeepingtheradiusthesamedrawanarccenteredonFthatintersectsthearccenteredonC,atH.
0168
183
A B
C
D
F
E
G
Step5:DrawlineCE,whichisparalleltolineABsincethealternateexterioranglesformedbythetransversalarecongruent.
Method3:AlternateExteriorAngles
ADGECFthereforeABCE
184
A B
C E
Herearethelineswithouttheconstructionlines.Method3:AlternateExteriorAngles
185
VideoDemonstratingConstructingParallelLineswithAlternateExterior
AnglesusingDynamicGeometricSoftware
Clickheretoseevideo
http://youtu.be/GnZ5E7i3qaQ
186
ParallelLineConstructionUsingPattyPaper
Step1:Drawalineonyourpattypaper.Labelthelineg.DrawapointnotonlinegandlabelthepointB.
gB
187
gB
ParallelLineConstructionUsingPattyPaper
Step2:FoldyourpattypapersothatthetwopartsoflineglieexactlyontopofeachotherandpointBisinthecrease.
188
Step3:Openthepattypaperanddrawalineonthecrease.Labelthislineh.
ParallelLineConstructionUsingPattyPaper
gB
h
189
Step4:ThroughpointB,makeanotherfoldthatisperpendiculartolineh.
ParallelLineConstructionUsingPattyPaper
gB
h
190
Step5:Openthepattypaperanddrawalineonthecrease.Labelthislinei.
Becauselinesiandgareperpendiculartolinehtheyareparalleltoeachother.Thereforelineilineg.
ParallelLineConstructionUsingPattyPaper
gB
h
i
191
VideoDemonstratingConstructingaParallelLineusingMenuOptionsof
DynamicGeometricSoftware
Clickheretoseevideo2
Clickheretoseevideo1
http://youtu.be/sBJBWp-61l0http://youtu.be/KiURcVkRGx0
192
C
A B
E
D
F
G
55 Thelinesinthediagrambelowareparallelbecauseofthe:A AlternateInteriorAnglesTheoremB AlternateExteriorAnglesTheoremC SameSideAnglesTheoremD CorrespondingAnglesPostulate
Ans
wer
0109
193
56 Thelinesbelowareshownparallelbythe:
A AlternateInteriorAnglesTheoremB AlternateExteriorAnglesTheoremC SameSideAnglesTheoremD CorrespondingAnglesPostulate
C
A
E
D
F
G
Ans
wer
A
194
57 Thebelowlinesareshownparallelbythe:A AlternateInteriorAnglesTheoremB AlternateExteriorAnglesTheoremC SameSideAnglesTheoremD CorrespondingAnglesPostultate
C
AD
FG
E
Ans
wer
195
PARCCSampleTestQuestions
TheremainingslidesinthispresentationcontainquestionsfromthePARCCSampleTest.Afterfinishingunit3,youshouldbeabletoanswerthesequestions.
GoodLuck!
ReturntoTableofContents
196
PARCCSampleTestQuestions
PARCCReleasedQuestion(EOY)
Topic:ParallelLines&Proofs
http://parcc.pearson.com/practice-tests/math/
197
58 CBDBFE
A GivenB DefinitionofcongruentanglesC VerticalanglesarecongruentD ReflexivepropertyofcongruenceE SymmetricpropertyofcongruenceF Transitivepropertyofcongruence
BA
D
E
F
G
C
H
Inthefigureshown,LineCFintersectslinesADandEHatpointsBandF,respectively.
Given:CBDBFEProve:ABFBFE
Ans
wer
A
198
59 CBDABF
A GivenB DefinitionofcongruentanglesC VerticalanglesarecongruentD ReflexivepropertyofcongruenceE SymmetricpropertyofcongruenceF Transitivepropertyofcongruence
BA
D
E
F
G
C
H
Inthefigureshown,LineCFintersectslinesADandEHatpointsBandF,respectively.
Given:CBDBFEProve:ABFBFE
Ans
wer
C
199
60 ABFBFEA GivenB DefinitionofcongruentanglesC VerticalanglesarecongruentD ReflexivepropertyofcongruenceE SymmetricpropertyofcongruenceF Transitivepropertyofcongruence
BA
D
E
F
G
C
H
Inthefigureshown,LineCFintersectslinesADandEHatpointsBandF,respectively.
Given:CBDBFEProve:ABFBFE
Ans
wer
F
200
BA
D
E
F
G
C
H
Inthefigureshown,LineCFintersectslinesADandEHatpointsBandF,respectively.
Given:CBDBFEProve:ABFBFE
Completedproofshownbelow.
Statement Reason
1 CBDBFE Given
2 CBDABF VerticalAnglesarecongruent
3 ABFBFE Transitivepropertyofcongruence
201
PARCCSampleTestQuestions
Circlethereasonthatsupportseachlineoftheproof.
PARCCReleasedQuestion(EOY)
Topic:ParallelLines&Proofs
http://parcc.pearson.com/practice-tests/math/
202
61 mCBD=mBFEA GivenB AnglesthatformalinearpairaresupplementaryC AnglesthatareadjacentaresupplementaryD ReflexivepropertyofequalityE SubstitutionpropertyofequalityF Transitivepropertyofequality
BA
D
E
F
G
C
H
InthefigureshownLineCFintersectslinesADandEHatpointsBandF,respectively.
Given:mCBD=mBFEProve:mBFE+ mDBF=180
Ans
wer
A
203
62 mCBD+mDBF=180
BA
D
E
F
G
C
H
InthefigureshownLineCFintersectslinesADandEHatpointsBandF,respectively.
Given:mCBD=mBFEProve:mBFE+ mDBF=180
A GivenB AnglesthatformalinearpairaresupplementaryC AnglesthatareadjacentaresupplementaryD ReflexivepropertyofequalityE SubstitutionpropertyofequalityF Transitivepropertyofequality
Ans
wer
B
204
63 mBFE+mDBF=180
A GivenB AnglesthatformalinearpairaresupplementaryC AnglesthatareadjacentaresupplementaryD ReflexivepropertyofequalityE SubstitutionpropertyofequalityF Transitivepropertyofequality
BA
D
E
F
G
C
H
InthefigureshownLineCFintersectslinesADandEHatpointsBandF,respectively.
Given:mCBD=mBFEProve:mBFE+ mDBF=180
Ans
wer
E
205
BA
D
E
F
G
C
H
InthefigureshownLineCFintersectslinesADandEHatpointsBandF,respectively.
Given:mCBD=mBFEProve:mBFE+mDBF=180
Statement Reason
1 mCBD=mBFE Given
2 mCBD+mDBF=180Anglesthatformalinearpairaresupplementary
3 mBFE+mDBF=180 SubstitutionPropertyofEquality
206
64 PARTAConsiderthepartialConstructionofalineparalleltorthroughpointQ.whatwouldbethefinalstepintheconstruction?
A DrawalinethroughPandSB DrawalinethroughQandSC DrawalinethroughTandSD DrawalinethroughWandS
Thefigureshowsliner,pointsPandTonliner,andpointQnotonliner.AlsoshownisrayPQ.
rTP
Q
rTP
Q
W
S
Ans
wer
PARCCReleasedQuestion(EOY)
http://parcc.pearson.com/#
207
65 PARTBOncetheconstructioniscomplete,whichofthereasonslistedcontributetoprovingthevalidityoftheconstruction?
A Whentwolinesarecutbyatransversalandthecorrespondinganglesarecongruent,thelinesareparallel.
B Whentwolinesarecutbyatransversalandtheverticalanglesarecongruent,thelinesareparallel.
C Definitionofsegmentbisector.D Definitionofananglebisector.
Thefigureshowsliner,pointsPandTonliner,andpointQnotonliner.AlsoshownisrayPQ.
rTP
Q
rTP
Q
W
S
Ans
wer
A
PARCCReleasedQuestion(EOY)
http://parcc.pearson.com/#
208
66 Thediagramrepresentsaportionofasmallcity.MapleStreetandPineStreetrunexactlyeasttowest.Oakavenuerunsexactlynorthtosouth.Allofthestreetsremainstraight.
A BirchStreetandElmStreetintersectatrightangles.
B MapleStreetandPineStreetareparallel.
C Ifmoreofthemapisshown,ElmStreetandOakAvenuewillnotintersect.
D PineStreetintersectsbothBirchStreetandElmStreet.E OakAvenueandMapleStreetareperpendicular.
Question1/7
PARCCReleasedQuestion(PBA)
Topic:Lines:Intersecting,Parallel&Skew
Whichstatementsmustbetruebasedonlyonthegiveninformation?Selectallthatapply.
Ans
wer
http://parcc.pearson.com/#
Attachments
constructparanotline.webloc
[InternetShortcut]URL=http://www.mathsisfun.com/geometry/construct-paranotline.html
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