1. 2.3 Complementary and Supplementary Angles

2. Definitions Complementary angles – the sum of their measures is 90˚
Each angle is the compliment of the other A
32˚
58˚ B

3. Definitions Supplementary angles – the sum of their measures is 180˚
Each angle is the supplement of the other
46˚ D
134˚ C

4. Identify Complements and Supplements
158˚
22˚
15˚
85˚
55˚
35˚

5. Definitions
Adjacent angles – have a common vertex and side, but no common interior points
Common side B
Common vertex

6. Identify Adjacent Angles3 4 5 6 1 2

7. Measures m A is a complement of C, and m A = 47˚. Find m C.
43˚
M P is a supplement of R, and m R = 36˚. Find m P.
144˚

8. Definitions
Theorem – a true statement that follows from other true statements

9. Theorem 2.1 Congruent Compliments Theorem
If two angles are complementary to the same angle, then they are congruent
m m = 90˚
m m =90˚
Then 1 2 3

10. Theorem 2.2 Congruent Supplements Theorem
If two angles are supplementary to the same angle, then they are congruent
m m = 180˚
m m = 180˚
Then 2 3 1

11. Use Theorems 7 and 8 are supplementary 8 and 9 are supplementary
Name a pair of congruent angles. 8 7 9

12. Guided Practice
Pg. 70 #1-7