1. 3.3 Parallel Lines and Transversals
CAS 4, 7
3.3 Parallel Lines and Transversals
Goal 1: Properties of Parallel Lines
Goal 2: Properties of Special Pairs of Angles

2. Postulate 15 Corresponding Angles Postulate
If two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent. 1 2

3. Theorems About Parallel Lines
Thm 3.4 Alternate Interior Angles Thm
If two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent. 3 4

4. Theorems About Parallel Lines (continued)
Thm 3.5 Consecutive Interior Angles Thm
If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementary 5 6
Are supplementary

5. Theorems About Parallel Lines (continued)
Thm 3.6 Alternate Exterior Angles Thm
If two parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruent. 7 8

6. Theorems About Parallel Lines (continued)j
Thm 3.7 Perpendicular Transversal Thm
If a transversal is perpendicular to one of the two parallel lines, then it is perpendicular to the other. h k

7. Ex. 1 Use properties of parallel lines to find the value of x.

8. Ex. 2 Line n and m are parallel. Solve for x.