Question

Triangle ABC is isosceles.

Triangle A B C is shown. The lengths of sides A C and A B are congruent.

What is true about the measure of angle B?

It is twice the measure of angle A.
It is twice the measure of angle C.
It is equal to the measure of angle A.
It is equal to the measure of angle C.

Answer 1

AB = AC, so the angles opposite those equal sides are equal. The angle opposite AB is angle C and the angle opposite AC is angle B, hence angle B = angle C.