Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
1
October 04, 2017
Oct 67:46 AM
Unit 1Lesson 13
Proofs involving Parallel lines
We will need to recall the different postulates and Theorems involving Parallel lines...Can you name the following types of angles from the diagram below???
1 234
5 6 7 8
91011
1 and 11
3 and 6
1 and 9
7 and 9
2 and 8
1.2.3.4.5.
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
2
October 04, 2017
Oct 31:07 PM
GivenCorresponding angles are when the lines are II
Vertical angles are
Transitive Property of
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
3
October 04, 2017
Oct 31:08 PM
note: You may not use the theorem you are trying to prove as part of your "Reasons"
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
4
October 04, 2017
Oct 31:09 PM
Prove: The Same Side-Exterior Angle Theorem
Given:
Prove:
a b1 and 3 are Supplementary
Statements Reasons1.
2.
3.
4.
5.
6.
7.
8.
9.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
5
October 04, 2017
Oct 31:10 PM
Given:
Prove: r || sm<3= 85o m<4 = 85o
Statements Reasons
r
s3
4
1.
2.
3.
4.
5.
6.
7.
8.
9.
1.
2.
3.
4.
5.
6.
7.
8.
9.
m<3 = 85o , m< 4 = 85o Given
m<3 = m<4when 2 angles are = to 850 they are equal in measure.
<3 ≅ <4 = implies
r ll s when alternate exterior angles are the lines are II.
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
6
October 04, 2017
Oct 31:11 PM
Given:
Prove:
Statement Reason1.2.3.4.5.6.7.8.
1.2.3.4.5.6.7.8.
<2 and <4 are supplementary
2
4
r
s
1
53r || s<2 and <4 are supplementary
<4 <5 vertical angles are given
m<1+m<4 = 180
m<4=m<5 implies =Sumplementary angles sum is 1800
m<2+m<5 = 180 substitution property
<2 & <5 are supplementary If 2 angles sum is 180, they are supplementary.
r II swhen sameside interior angles are supplementary, the lines are II
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
7
October 04, 2017
Oct 31:12 PM
Given:
Prove:
Statement Reason1.2.3.4.5.6.7.8.
1.2.3.4.5.6.7.8.
n || k
<1 ≅ <3<2 ≅ <3
<1 ≅ <2
m || k
Given
Transitive property of congruency
Givenm || n
m
nk
12
3
m || nn || k
m || k
corresponding angles are when lines are II
corresponding angles are when lines are II
when corresponding angles are , the lines are II
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
8
October 04, 2017
Oct 31:12 PM
1 2
3 4
A
C
B
D
Given: AB ll DC, <1 ≅<2
Prove: <3 ≅ <4
Statements Reasons
AB ll DC, <1 ≅<21)1) Given
2) 2) corresponding angles are when lines are II
3) <4 <1 3) Transitive Property
<2 <4
4) <1 <3 4) corresponding angles are when lines are II
5) <4 <3 5) Transitive Property
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
9
October 04, 2017
Oct 31:12 PM
12
34
5 l
m
n k
Given: l ll m, n ll k
Prove: <1 ≅ <5Statements Reasons
1) l ll m, n ll k 1) Given
2) <1 <3 2) corresponding angles are when lines are II <3 <5
3) <1 <5
3) Transitive Property
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
10
October 04, 2017
Oct 31:12 PM
12
34
5 l
m
n kGiven: <3 ≅<4, m ll l
Prove: <2 ≅<4
Statements Reasons1) <3 ≅<4, m ll l 1) given
3) <2 <33) when line are parallel, alternate interior angles are .
2) n II k 2) when alternate interior angles are , the lines are II
4) <2 <4 4) Transitive Property of
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
11
October 04, 2017
Oct 31:21 PM
1 2 3
4 5
a
b
c Proof...that the sum of the interior angles of a triangle add up to 180o
statements reasons1) Draw line a, parallel to line b...so a b
1) Through any point, there exists a line parallel to a given line
2) m<1=m<4alternate interior angles are = in measure when the lines are parallel
m<5=m<33)
2)
3) same as reason 2
4) m<1+m<2+m<3=1800 4) a straight angles measure 1800
5) m<4+m<2+m<5=1800 5) substitution property
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
12
October 04, 2017
Oct 612:57 PM
Given:
Prove: 1A
B
C2
<1 is an exterior angle
m<1 = m<A + m<B
Statements Reasons1.2.3.4.5.6.7.8.9.
1.2.3.4.5.6.7.8.9.
given<1 is an exterior angle
m<1 + m<2 = 180o
m<2 +m<B +m<A = 180o
m<1 + m<2 = m<2 +m<A + m<B
m<1 = m<A + m<B
<1&<2 are a linear pair 2 angles that share a common vertex and whose noncommon sides are opposite rays, form a linear pair.
<1& <2 are supplementary If 2 angles form a linear pair, then they are supplementary.Supplementary angles add up to 180 degrees.
The 3 angles of any triangle sum to 180 degrees.
Substitution Property
Subtraction property of equality.
Unit 1 Lesson 13 Proving Theorems involving parallel and perp lines WITH ANSWERS!.notebook
13
October 04, 2017
Oct 61:05 PM
Homework Unit 1 Lesson 13found on the website