1. Warm-Up Find the value of x. x + 25 3x - 3

2. GEOMETRY 4-8 Isosceles and Equilateral Triangles

3. Parts of an Isosceles Triangle Base: the side opposite the vertex angle Base angle Leg: a congruent side Vertex angle: formed by the two legs

4. Theorem Isosceles Triangle Theorem: If two sides of a triangle are congruent, then the angles opposite those sides are congruent. If Then

5. Examples Find the value of x. 55° x + 4° 1) 2)

6. Equilateral Triangles Equilateral Theorem: All equilateral triangles are equiangular. All equiangular triangles are equilateral.

7. Examples Find the value of x.Find the value of y.