1. 3-2 Proving Lines Parallel
Geometry

2. Converse of the Corresponding Angles Postulate
If two lines and a transversal form corresponding angles that are congruent, then the two lines are parallel.

3. Converse of the Alternate Interior/Exterior Angles
If two lines and a transversal form alternate interior/exterior angles that are congruent, then the two lines are parallel.

4. Converse of the Same-Side Interior Angles Theorem
If two lines and a transversal form same-side interior angles that are supplementary, then the two lines are parallel.

5. THEOREM 3-5:
If two lines are parallel to the same line, then they are parallel to each other.

6. THEOREM 3-6:
In a plane, if two lines are perpendicular (90°) to the same line, then they are parallel.

7. Ex. 1: For what value of x is a parallel to b.

8. Ex. 2: For what value of x is l parallel to m.

9. Ex. 3: For what value of x is a parallel to b.

10. Ex. 4: For what value of x is a parallel to b.