10-2 Complementary and Supplementary Angles.notebook1
102: Complementary and Supplementary Angles
Please have your homework assignment out on your desk.
You have 5 minutes to complete the problems below.
102 Complementary and Supplementary Angles.notebook
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February 24, 2014
Assignment p. 512513, #117, 21,22,26
1. MNP, PNM, N, 1, obtuse
2. RST, TSR, S, 3, acute 3. 1 and
3, or 2,and 4
4. ABC, CBA, B, 4, acute
5. DEF, FED, E, 5, right
6. XYZ, ZYX, Y, 6, obtuse
7. MNP, PNM, N, 7, straight
8. HKI, IKH, K, 8, obtuse
9. RTS, STR, T, 9, acute
10. Vertical
11. Neither
12. Adjacent
13. Adjacent
14. Neither
15. Vertical
17. 1 and 2
3
Main Idea: identify complementary and supplementary angles and find
missing angle measures.
Vocabulary: • complementary angles two angles are complementary
if the sum of their measures is 90 degrees. • supplementary angles
two angles are supplementary if the sum of their measures is 180
degrees.
102 Complementary and Supplementary Angles.notebook
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February 24, 2014
Complementary angles Two angles are complementary if the sum of
their measures is 90 degrees. One of the complementary angles is
said to be the complement of the other. Example: These two angles
are complementary.
Note that these two angles can be "pasted" together to form a right
angle!
102 Complementary and Supplementary Angles.notebook
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90o
45o45o
6
x
x
Solution
If the sum of the measure of 2 angles is 90o
the angles are called complementary angles.
102 Complementary and Supplementary Angles.notebook
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27o
8
February 24, 2014
Supplementary angles Two angles are supplementary if the sum of
their measures equals 180 degrees. One of the supplementary angles
is said to be the supplement of the other. Example: These two
angles are supplementary.
Note that these two angles can be pasted together to form a
straight line!
102 Complementary and Supplementary Angles.notebook
9
90o
45o45o
10
S
S
Sx
x
Solution
If the sum of the measure of 2 angles is 180o
the angles are called supplementary angles.
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12
February 24, 2014
7x + 5x = 90 12x = 90
x = 7.5 The larger angle is 52.5o
The smaller angle is 37.5o
5x + x = 90 6x = 90 x = 15
The smaller angle is 15o
The larger angle is 75o
Word problems
Two angles are complementary. The larger angle is 5 times
greater than the smaller angle. Find the measure of the 2 angles.
Two angles are complementary. The measure of the angles
are in a ratio of 7:5. Find the measure of the angles.
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x = 34
Supplement is 146o
8x + x = 180 9x = 180
x = 20 The smaller angle is 20o
The larger angle is 160o
Word problems
Two angles are supplementary. The larger angle is 8 times
greater than the smaller angle. Find the measure of the 2 angles.
The measure of the supplement of an angle is 10o more than
four times the original angle. Find the measure of the two angles.
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p. 516517, #113, 23 and 24
Quiz tomorrow over Lessons 101 and 102
(Angle Relationships, Complementary and
Supplementary Angles)
102 Complementary and Supplementary Angles.notebook
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1. Supplementary
2. Complementary
Subject Mathematics Grade 7 Strand Geometry
Objective The objective of this lesson is to compute angle
complements and supplements.
Page 1 Title page.
Page 2 Ask a student volunteer to identify the diagrams which show
complementary angles. The letter C in the blue circle can be used
to identify the angles. If students need to review the definition
of a complementary angle this can be dragged from the side of the
screen.
Page 3 Solution to previous page. Ask students to explain why the
angles marked with an ‘x’ are not complementary angles.
Page 4 “How do you find the measure of the complement of an angle?”
(Subtract its measure from 90 degrees.) Find the complement of the
angles. Write the answers in the blue boxes using the Pen Tool.
Click each of the answer buttons to check your answer.
Page 5 Solve the word problems involving complementary angles. Drag
the hint button from the left of the page.
Page 6 Ask a student volunteer to identify the diagrams which show
supplementary angles. The letter C in the blue circle can be used
to identify the angles. If students need to review the definition
of a supplementary angle this can be dragged from the side of the
screen.
Page 7 Solution to previous page. Ask students to explain why the
angles marked with an ‘x’ are not supplementary angles.
Page 8 “How do you find the measure of the supplement of an angle?”
(Subtract its measure from 180 degrees.) Find the supplement of the
angles. Write the answers in the blue boxes using the Pen Tool.
Click each of the answer buttons to check your answer.
Page 9 Solve the word problems involving supplementary angles. Drag
the hint button from the left of the page.
Page 10 “Which angles facts did you use to solve this
problem?”
SMART Notebook
Page 2: Feb 7-11:02 AM
Page 3: Mar 15-8:35 AM
Page 4: Feb 28 - 10:40 PM
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Page 6: Page 3
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