# What is the measure of a base angle of an isosceles triangle if its vertex angle measures 50 degrees?

Nov 14, 2015

The measure of one base angle is $65$ degrees.

#### Explanation:

We know that an isosceles triangle is composed of a vertex angle and two base angles. The base angles are congruent to each other. We also know that the sum of a triangle's angles is $180$ degrees.

Our first thing to do is subtract $50$ from $180$. we are left with $130$ degrees for both base angles.

We divide $130$ by $2$ and get $65$ degrees. That means that each base angle is $65$ degrees. We can check our work by adding all angle measures together.