Chapter 4 - Congruent Triangles - Common Core Cumulative Standards Review - Selected Response - Page 278: 1

B

The isosceles triangle theorem proves that if two sides of a triangle are congruent, then their corresponding angles are congruent also. The converse of this theorem is that if two angles of a triangle are congruent, then their corresponding sides are congruent. Because we are using two congruent angles to prove that their corresponding sides are congruent, we are using the converse of the isosceles triangle theorem.