1. D B A C 3.2—Isosceles and Equilateral Triangles

2. Objective: Use properties of _______________, and ________________triangles. equilateral Vocabulary: Perimeter of a Triangle: the ________ of the ______________ of all the sides of a triangle. sumlengths isosceles

4. Examples: Find the values of x and y. 1) x° y° What do I know about the sides? Equal or Unequal? What do I know about the angles?

5. Examples: Find the values of x and y. 2) What do I know about the sides? Equal or Unequal? 6x – 4 20

6. Examples: Find the values of x and y. 3) What do I know about the sides? Equal or Unequal? What do I know about the angles?

7. 4. 5. What do I know about the sides? Equal or Unequal? What do I know about the angles? What do I know about the sides? Equal or Unequal? What do I know about the angles?

8. 6. 7. What do I know about the sides? Equal or Unequal? What do I know about the angles? What do I know about the sides? Equal or Unequal? What do I know about the angles?

9. The vertex angle of an isosceles triangle measures (a + 15)°, and one of the base angles measures 7a°. Find a and each angle measure. 8.

10. A B 9.

11. C D D E 10.