If two sides of a triangle are congruent, then the angles opposite them are congruent.
1. Triangle ABC. 1. Given.
2. AB = BC. 2. Given.
3. Draw angle bisector of / B to intersect 3. Every angle has one angle bisector.
side CA at point D.
4. / ABD = / CBD 4. Definition of angle bisector.
5. BD = BD 5. Reflexive Property.
6. Triangle ABD = triangle CBD. 6. SAS
7. / A = / C 7. Corresponding parts of congruent
triangles are equal.