1. Parallel and Perpendicular Lines
Chapter 3
Parallel and Perpendicular Lines

2. Section 4 Parallel Lines and Transversals

3. In the photograph of the tennis court, the angle the sideline makes with the service line is the same as the angle it makes with the base line. The photograph illustrates a postulate about angles and parallel lines.

5. Example 1: Find Measures of Corresponding Angles Find the measure of the numbered angle.

6. Checkpoint: Find Measures of Corresponding Angles Find the measure of the numbered angle.

8. Example 2: Find Measures of Alternate Interior Angles Find the measure of <PQR.

9. Checkpoint: Find Measures of Alternate Interior Angles Find the measure of the numbered angle.

11. Example 3: Find Measures of Alternate Exterior Angles Find the measures of <1 and <2.

12. Checkpoint: Use Angle Relationships Find the measure of the numbered angle.

13. Use the diagram below. Tell whether the angles are congruent or not congruent. Explain.
<1 and < <3 and <4
3. <4 and < <2 and <7
5. <3 and < <3 and <8

15. Example 4: Find Measures of Same-Side Interior Angles Find the measure of the numbered angle.

16. Example 5: Use Algebra with Angle Relationships Find the value of x.

17. Checkpoint: Use Algebra with Angle Relationships Find the value of x.