Angle formed by one side of a convex polygon and the extension of an adjacent side.

An angle inside a polygon that is not adjacent to an exterior angle is called a

**remote interior angle**.### Example

In the figure below, angle *BDE* is an exterior angle of polygon *ABCD*. It is formed by side *BD* and the extension of side *CD*.

### Properties

- The sum of the degree measures of the exterior angles of a convex polygon is always equal to 360°.

- The measure of an exterior angle of a triangle is equal to the sum of the measures of the remote interior angles of the triangle.
In the figure shown above, the measure of the exterior angle at vertex

*C*is equal to the sum of the measures of the remote interior angles at vertices*A*and*B*.