1. Lesson 4-2 Angles of Triangles

2. Concept 1

3. Concept 2

4. Example 1 Use the Triangle Angle-Sum Theorem SOFTBALL The diagram shows the path of the softball in a drill developed by four players. Find the measure of each numbered angle.

5. Example 1 Use the Triangle Angle-Sum Theorem

6. Example 1 A.95 B.75 C.57 D.85 Find the measure of  3.

7. Concept 3

8. Example 2 Use the Exterior Angle Theorem GARDENING Find the measure of  FLW in the fenced flower garden shown.

9. Example 2 A.30 B.40 C.50 D.130 The piece of quilt fabric is in the shape of a right triangle. Find the measure of  ACD.

10. Concept 5

11. Example 3 Find Angle Measures in Right Triangles Find the measure of each numbered angle.

12. Example 3 Find Angle Measures in Right Triangles

13. Example 3 A.50 B.45 C.85 D.130 Find m  3.

14. Vocabulary Auxiliary line-Extra line or segment drawn in a figure to help analyze geometric relationships. Exterior angle-Formed by one side of the triangle and the extension of an adjacent side. Remote interior angles- Each exterior angle of a triangle that are not adjacent to the exterior angle. Flow proof-Use statements written in boxes and arrows to show the logical progression of an agrument.