1. 3-3 Proving Lines 
Geometry

2. Post.3-3-1 – Corresponding s Postulate (Converse)
If 2 lines are cut by a transversal so that corresponding s are , then the lines are .
** If ___ ____, then l m. 1 2 l m

3. 3-3-3 – Converse of AIA Thm
If 2 coplanar lines are cut by a transversal so that a pair of alt. int. s are , then the 2 lines are .
** If __ ___, then l m. 1 2 l m

4. 3-3-4 – Converse of AEA Thm
If 2 coplanar lines are cut by a transversal so that a pair of alt. ext. s are , then the 2 lines are .
** If 1  2, then l m. l m 1 2

5. 3-3-5 – Converse of SSIA Thm
If 2 coplanar lines are cut by a transversal so that a pair of same side int. s are supplementary, then the lines are .
**If ___ & ___ are supplementary, then l m. l m 1 2

6. Ex 1: Based on the info in the diagram, is p q ? If so, give a reason.

7. Ex 2: Find the value of x that makes j  k .
The angles marked are ____________ interior s.
Therefore, they are _________________.
xo xo
j k

8. Ex 3: Find the value of x that makes j  k .
The angles marked are ____________ interior s.
Therefore, they are _________________.
(10x+8)o (25x -3)°
j k

9. Ex 4: Proving Lines Parallel
Given: ∠1≌∠4,
∠3 & ∠4 are supplementary.
Prove: l  m
l m n

10. Proving Lines Parallel

11. Assignment