Question

6) The exterior angle to the vertex angle of an isosceles triangle has measure 250. What is

the measure of each base angle of the triangle?

Answer 1

12.5°

Explanation:

In any triangle, an exterior angle is the sum of the remote interior angles.

The exterior angle at the vertex angle of an isosceles triangle will be the sum of the two congruent base angles. Hence, each base angle is half the value of the exterior angle.

25° = 2b

b = 25°/2 = 12.5° . . . . the measure of each base angle