## Geometry and Trigonometry## Plane Geometry |

## What are the parts of right and isosceles triangles? |

There are special names for the parts of a right triangle. The *hypotenuse* is the side opposite the 90 degree angle—the side that will always be the triangle’s longest. The shorter sides are called the *legs.*

Similar to the right triangle, the isosceles triangle has specific names for its angles and sides: Congruent (equal) sides are, as with the right triangle, called the *legs;* the angle formed by these two legs is called the *vertex angle;* and the *base* is the side opposite the vertex angle. The two angles that are formed by the base and the legs are called the triangle’s *base angles.*