**Base angles**

An **isosceles triangle** is a triangle with two sides of equal length. The** two equal** sides are called the** legs** and the third side is called the **base. **

The angles at the base are called the **base angles,** and the angle opposite the base is called the **vertex angle.**

In an isosceles triangle, the **apex is the vertex** where the two sides of equal length meet, opposite the unequal third side.