1. Section 3-3 Parallel Lines and Transversals

2. Properties of Parallel Lines

3. Corresponding angles postulate If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent.

4. Example: 1 2

5. Alternate interior angles Theorem If two parallel lines are cut by a transversal, then the pairs of alternate interior angle are congruent.

6. Example: 3 4

7. consecutive interior angles Theorem If two parallel lines are cut by a transversal, then the pairs of consecutive interior angle are supplementary.

8. Example: 5 6

9. Alternate Exterior angles Theorem If two parallel lines are cut by a transversal, then the pairs of alternate exterior angle are congruent.

10. Example: 7 8

11. Perpendicular transversal Theorem If a transversal is perpendicular to one of two parallel lines, then it is perpendicular to the other.

12. Example: a b l therefore