1. M217 Section 1.3 Measuring Angles

2. Angle Terminology: Angle: 2 different rays with the same endpoint Vertex: Common endpoint - A Sides: Two rays – Naming: Interior: Exterior: On: C AB E I 2

3. Angle Measures, Congruency Angles are measured using a protractor If two angles have the same measure, then they are congruent angles and are marked with arcs the

4. 4 Classifying Angles by Measure TermDefinitionExample Acute Right Obtuse Straight

5. Angle Addition Postulate If P is on the interior of angle RST, then Basically: two parts = 1 whole

6. T is on the interior of angle PQR

7. Defn: Angle Bisector An Angle Bisector is a ray that divides an angle into two congruent angles

8. Angle Bisector

9. Reading a Protractor Notice two sets of numbers Now try #4 – 6 on page 24. Then begin HW 4. 15 ◦, acute 5. 105 ◦, obtuse 6. 110 ◦, obtuse