3.4 Proving Lines 

1. 3.4 Proving Lines  p. 150

2. Post. 3-4 – Corresponding s • If 2 lines are cut by a transversal so that corresponding s are , then the lines are . ** If 1  2, then l m. 1 2 l m

3. Thm 3.5 – Alt. Ext. s Converse • If 2 lines are cut by a transversal so that alt. ext. s are , then the lines are . ** If 1  2, then l m. l m 1 2

4. Thm. 3.6 – Consecutive Int. s Converse • If 2 lines are cut by a transversal so that consecutive int. s are supplementary, then the lines are . ** If 1 & 2 are supplementary, then l m. l m 1 2

5. Thm. 3.7 – Alt. Int. s Converse • If 2 lines are cut by a transversal so that alt. int. s are , then the lines are . ** If 1  2, then l m. 1 2 l m

6. Yes, alt. ext. s conv. No No Ex: Based on the info in the diagram, is p q ? If so, give a reason. p q p q p q

7. The angles marked are consecutive interior s. Therefore, they are supplementary. x + 3x = 180 4x = 180 x = 45 Ex: Find the value of x that makes j  k . xo 3xo j k

8. Assignment p. 149 (1, 3, 7-13, 19-27)