1. quiz Tell whether the pair of triangles is congruent or not and why. 1. 2.

2. You can not prove Triangle congruent with Side-Side- Angle (SSA) and Angle-Angle-Angle (AAA)

3. *Use Isosceles and Equilateral Triangles Section 4.7

4. Triangles Isosceles – a triangle with at least two congruent sides. Vertex angle Base leg Base angle

5. Equilateral – a triangle with 3 congruent sides Equiangular - a triangle with 3 congruent angles

6. Base Angles Theorem If two sides of a triangle are congruent, then the angles opposite them are congruent.

7. Converse of Base Angles Theorem If two angles of a triangle are congruent, then the sides opposite them are congruent.

8. Corollaries (a statement that can be proved easily using the theorem) Corollary to the Converse of Base Angles Theorem: If a triangle is equiangular, then it is equilateral. Corollary to the Base Angles Theorem: If a triangle is equilateral, then it is equiangular.

9. Example1: Find x and y.

10. Homework 4.7 pg. 267-268 #7-17, 23-25