1. PROVING LINES PARALLEL

2. CONVERSE OF  … Corresponding Angles Postulate: If the pairs of corresponding angles are congruent, then the lines are parallel  If Angle 2 is congruent to angle 6 then then L is parallel to M. The same is true for any other pair of Corresponding angles.

3. CONVERSE OF  …Alt. Interior Angles Theorem: If the pairs of ALT. Interior angles are congruent, then the lines are parallel  If angle 3 is congruent to angle 6 or angle 4 is Congruent to angle 5, then the lines are parallel.

4. CONVERSE OF  …Alt. Exterior Angles Theorem: If the pairs of ALT. Exterior angles are congruent, then the lines are parallel  If angle 1 is congruent to angle 8 or angle 2 congruent to angle 7, then the lines are parallel

5. CONVERSE OF  …Same Side Interior Theorem: If the pairs of same side interior angles are supplementary, then the line are parallel  If angle 3 + angle 5 = 180 or angle 4 + angle 6 = 180 then the line are parallel.

6. EXAMPLE 1

7. EXAMPLE 2

8. EXAMPLE 3