1. ___ let
Kayln Marie Van Asperen-Yost -

2. ( & )
Ona Strickland

3. USE ISOSCELES AND EQUILATERAL TRIANGLES
Warm up!
USE ISOSCELES AND EQUILATERAL TRIANGLES
For questions 1-3, classify each triangle by its sides.
2 cm, 2 cm, 2 cm ft, 11 ft, 7 ft
3. 9m, 8m, 10 m
Equilateral
Isosceles
Scalene

4. Vocabulary Isosceles Triangle: Legs: Base: Vertex Angle: Base Angles:
has at least 2  sides
The 2 sides that are congruent
The side that is not congruent (if it only has 2  sides) S O I
The angle between the 2 legs of the triangle
The 2 angles attached to the base
I and 0

5. BASE ANGLES THEOREM C A C B

6. CONVERSE OF BASE ANGLES THEOREM

7. Example 1 In ΔFGH, FH GH. Name two congruent angles.
 G is congruent to F

8. GUIDED PRACTICE Complete the statement
1. If HG HK, then ______ ________
2. If KHJ KJH, then ______ _______
G HKG
Extra: What are the base angles of an isosceles right triangle?

9. A triangle is equilateral if and only if it is ___________
equiangular
equilateral
A triangle is equilateral if and only if it is ___________
equiangular

10. Example 2:
Find the measures of R, S, T
Is it possible for an equilateral triangle to have an angle measure other than 60? No

11. Example 3:
Find the values of x and y in the diagram.

12. Example 4:
Find the values of x and y in the diagram.

13. Practice Problems:

14. Find the values of x and y.