1. 1-5: Exploring Angle Pairs

2. Types of Angle Pairs Adjacent Angles Vertical Angles Complementary Angles Supplementary Angles Two coplanar angles with a: _______________, ________________, _______________________________ Two angles whose sides are __________ ______ Two angles whose measures have a sum of _______ common sidecommon vertex no common interior points oppositerays

3. Example 1: Use the diagram below. Is each statement true? Explain. a. and are adjacent angles. b. and are vertical angles. c. and are supplementary. Yes, they have a common side No, they don’t share two pairs of opposite rays Yes, the sum of the angles is 180°

4. Assumptions About Angles Assumptions you can make: 1.Angles are adjacent 2.Angles are adjacent and supplementary 3.Angles are vertical angles Assumptions you can’t make: 1.Angles or segments are congruent 2.An angle is a right angle 3.Angles are complementary

5. Postulate 1-9: Linear Pair Postulate A Linear Pair of angles are angles that are both supplementary and adjacent. Ex 2 What are the measures of and ?

6. Theorem 2-1: Vertical Angle Theorem Vertical angles are congruent and Example 3: What is the value of x? What are the angle measures?

7. Angle Bisector A ________ which divides an angle into ______ _______________ angles. ray two congruent is an angle bisector. Example 4: bisects. If, what is ?

8. Homework: p. 38 # 7-23, 27-32