1. 12.1 Complementary and Supplementary Angles Homework: p689, #12-22 even

2. Key Terms Complementary Angles: __________________________________ Supplementary Angles: __________________________________ Complement: __________________________________ Supplement:__________________________ _____________________________ Two angles that add to equal 90° Two angles that add to equal 180° To find a complement, subtract the given measure from 90° To find a supplement, subtract the given measure from 180°

3. Example 1: Identify Complements and Supplements Determine whether the angles are complementary, supplementary, or neither. 1. m  1 = 48° m  2 = 42° 2. m  3 = 125° m  4 = 55°

4. Checkpoint Determine whether the angles are complementary, supplementary, or neither. 1. m  1 = 63° m  2 = 27° 2. m  3 = 146° m  4 = 44° 3. m  5 = 95° m  6 = 85°

5. Keywords Adjacent angles : ____________________________________ ___________________________________ Example: Two angles that share the same side

6. Example 2: Identify Adjacent Angles List the numbered angles that are adjacent and then list the nonadjacent angles. Adjacent Angles Non-adjacent Angles

7. Example 3: Measures of Complements and Supplements a.)  A is a complement of  C, and m  A=47 °. Find m  C b.)  P is a supplement of  R, and m  R=36 °. Find m  P.

8. Checkpoint 4.)  B is a complement of  D, and m  D=79 °. Find m  B 5.)  G is a supplement of  H, and m  G=115 °. Find m  H.

9. Closure Describe what complementary angles are. Describe what supplementary angles are.

10. Connection to Algebra Find the value of x in the figure. Then find the unknown angle measures. 1. 3. 2.