1. Classifying Triangles Angles of Triangles
Chapter 4.1 and 4.2
Classifying Triangles
Angles of Triangles

2. Concept

3. A. Classify the triangle as acute, equiangular, obtuse, or right.
Classify Triangles by Angles
A. Classify the triangle as acute, equiangular, obtuse, or right.

4. B. Classify the triangle as acute, equiangular, obtuse, or right.
Classify Triangles by Angles
B. Classify the triangle as acute, equiangular, obtuse, or right.

5. Classify Triangles by Angles Within Figures
Classify ΔXYZ as acute, equiangular, obtuse, or right. Explain your reasoning.

6. Example 2 Classify ΔACD as acute, equiangular, obtuse, or right.
A. acute
B. equiangular
C. obtuse
D. right

7. Concept

8. Classify Triangles by Sides Within Figures
If point Y is the midpoint of VX, and WY = 3.0 units, classify ΔVWY as equilateral, isosceles, or scalene. Explain your reasoning.

9. If point C is the midpoint of BD, classify ΔABC as equilateral, isosceles, or scalene.
A. equilateral
B. isosceles
C. scalene

10. Finding Missing Values
ALGEBRA Find the measures of the sides of isosceles triangle KLM with base KL. __

11. ALGEBRA Find x and the measure of each side of equilateral triangle ABC if AB = 6x – 8, BC = 7 + x, and AC = 13 – x.
A. x = 10; all sides are 3.
B. x = 6; all sides are 13.
C. x = 3; all sides are 10.
D. x = 3; all sides are 16.

12. Prove it!

13. 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.

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

15. Concept 3

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

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

19. Concept 5

20. Find the measure of each numbered angle.
Find Angle Measures in Right Triangles
Find the measure of each numbered angle.

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