### What is an angle?

An angle is two rays that share a $\blueD{\text{vertex}}$.

Intersecting lines or line segments also form angles.

## Practice: Identifying an angle

## Measuring angles

Angles are measured in degrees.

The wider an angle is open, the greater its measure. If you compare these two angles, the first one is open wider.

So, the measure of this angle

is greater than the measure of this angle.