1. Parallel Lines and Transversals

2. Congruent Angles Angles that have the same measurement

3. Parallel Lines Two lines that always stay the same distance apart. (they never touch)

4. Perpendicular Lines Cross perfectly so that all four angles are 90 degrees

5. Transversal Intersects two parallel lines to form many sets of congruent angles. We have special names for these relationships transversal

6. Vertical Angles All vertical angles are congruent (they have the same measurement) Angles 1 and 2 are vertical angles. So are angles 3 and 4

7. See if you can spot them Angles 1 and 3, and angles 2 and 4

8. Corresponding angles When you draw parallel lines and a transversal, these angles have the same measure and position on each line Corresponding angles

9. Alternate Interior Angles Alternate Interior angles Key Words: Alternate and Interior

10. Alternate Exterior Angles Alternate Exterior angles Key Words: Alternate and Exterior

11. Consecutive Interior Angles Consecutive Interior angles Key Words: Consecutive and Interior

12. Finding Missing Angles If you are given one angle measurement, you can find the rest of the measurements using the relationships.

13. 40°

14. 130°