1. 3.4 Parallel Lines and Transversals
Goal:
Find congruent angles formed when a transversal cuts parallel lines.

2. Postulate 8 Corresponding Angles Postulate
If two parallel lines are cut by a transversal, then corresponding angles are congruent. t 1 2 j 3 4
If , then the following are true: 5 6 k 7 8

3. Find Measures of Corresponding Angles
Find the measure of the numbered angle.

4. Theorem 3.5 Alternate Interior Angles Theorem
If two parallel lines are cut by a transversal, then alternate interior angles are congruent. t 1 2 j 3 4
If , then the following are true: 5 6 k 7 8

5. Find Measures of Alternate Interior Angles
Find the measure of <PQR.

6. Theorem 3.6 Alternate Exterior Angles Theorem
If two parallel lines are cut by a transversal, then alternate exterior angles are congruent. t 1 2 j 3 4
If , then the following are true: 5 6 k 7 8

7. Find Measures of Alternate Exterior Angles
Find the measures of <1 and <2.
Linear Pair Postulate
Substitution Property of =
Subtraction Property of =

8. Theorem 3.7 Same-side Interior Angles Theorem
If two parallel lines are cut by a transversal, then same-side interior angles are supplementary. t 1 2 j 3 4
If , then the following are true: 5 6 k 7 8

9. Find Measures of Same-side Interior Angles
Find the measure of the numbered angle.

10. Use Algebra with Angle Relationships
Find the value of x.
Corresponding Angles Postulate
Subtraction Property of Equality

11. Homework
3.4 pg. 132
16-42 Even