**4.8 Isosceles and Equilateral Triangles**

**Definitions:**

Legs- Congruent sides of an isosceles triangle

Legs

**Vertex Angle**- The angle formed by the legs

**Base Angles**- the two angles that have the base as a side

**Theorems/Corollaries:**

Isosceles Triangle Theorem- If two sides of a triangles are congruent, then the angle opposite the sides are congruent

Isosceles Triangle Theorem

**Converse of Isosceles Triangle Theorem**- If two angles of a triangle are congruent, then the sides opposite those angles are congruent

**Equilateral Triangle Corollary**- If a triangle is equilateral, then it is equiangular Equiangular Triangle Corollary - If a triangle is equiangular, then it is equilateral

**Examples:**