1. Line and Angle Relationships Sec 6.1 GOALS: To learn vocabulary To identify angles and relationships of angles formed by tow parallel lines cut by a transversal

2. l BA Line Ray Angle AB A B C sides vertex Vocabulary

3. Types of Angles Acute angles – angles that have measures between 0 and Right angles – angles that have measures equal to Obtuse angles – angles that have measures between Straight angles – angles that have measures equal to

4. Special Pairs of Angles Vertical angles – opposite angles formed by intersecting lines. Vertical angles are congruent.

5. Special Pairs of Angles Adjacent angles – angles that have the same vertex, share a common side, and do not overlap. A B C

6. Special Pairs of Angles Complementary angles – angles whose sum is A B C D

7. Special Pairs of Angles Supplementary angles – angles whose sum is AB

8. Examples

9. Perpendicular Lines Perpendicular lines – lines that intersect at right angles k h

10. Parallel Lines Parallel lines – two lines in a plane that never intersect or cross k h

11. 7 Transversal A line that intersects two or more other lines is called a transversal. Eight angles are formed when a transversal intersect two lines. 8 43 65 2 1 t

12. 7 Corresponding Angles Postulate Corresponding angles are those in the same position on the two lines in relation to the transversal. If two parallel lines are cut by a transversal, then corresponding angles are congruent. 8 43 65 2 1

13. 7 Alternate Interior Angles Theorem Alternate interior angles are those on opposite sides of the transversal and inside the other two lines. If two parallel lines are cut by a transversal, then alternate interior angles are congruent. 8 43 65 2 1

14. 7 Alternate Exterior Angles Theorem Alternate exterior angles are those on opposite sides of the transversal and outside the other two lines. If two parallel lines are cut by a transversal, then alternate exterior angles are congruent. 8 43 65 2 1

15. Example Given: Find: x k h

16. Example Given: Find: x and the angle measure k h

17. Example Given: Find the angles shown. 4 35 2 118° k h

18. Students Given: Find: All other angle measures k h

19. Homework Page 259 13-15, 19-22, 30-33, 47-49