1. Isosceles and Equilateral Triangles Chapter 4-8

2. Theorems For Isosceles and Equilateral Triangles Isosceles Triangle Theorem If two sides of a triangle are congruent, then the angles opposite those sides are also congruent. Converse of Isosceles Triangle Theorem If two angles of a triangle are congruent, then the sides opposite those angles are also congruent.

3. Theorems For Isosceles and Equilateral Triangles Equilateral Triangles Theorem If a triangle is equilateral, then it is also equiangular. Converse Equilateral Triangles Theorem If a triangle is equiangular, then it is also equilateral.

4. Example Find each angle measure. A B C 38 o x o 1. m A = 2. m B = 3. m C =

5. Example Find each angle measure. A B C (3x+15) o 1. m A = 2. m B = 3. m C =

6. Example Find each side measure. J K L 2t + 1 1. JK = 2. LJ = 3. KL = 4t – 8

7. Examples B. Name 2 unmarked congruent segments Using the picture below, answer the questions. A. Name 2 unmarked congruent angles

8. L Examples Given: LM = LP ; N is the midpoint of MP Prove: M = P M N P Statements 1. 2. 3. 4. 5. 6. Reasons 1. 2. 3. 4. 5. 6.