1. An angle inside a polygon
Interior Angle:
To find the sum of the measures of the interior angles
of a convex n-gon, you can use a formula:
or you can
Find the measures of sum of the interior angles of the given regular polygon.
Find the measure of an interior angle of the given regular polygon.
An angle inside a polygon
Cut the polygon into triangles using diagonals. Multiply the number of triangles by 180 degrees.
NOTE! Divide either by the number of angles to find the measure of an interior angle.

2. Angle formed when the side of a polygon is extended.
Exterior Angle:
Remember!
The sum of the measures of the exterior angles of any polygon is:
5. Find in the diagram The diagram shows a teapot in the shape of
a regular hexagon. Find
7. Find the unknown angle measure in the diagram.
Angle formed when the side of a polygon is extended.
It is adjacent to the interior angle.
An interior angle and an exterior angle at the same vertex form a straight angle. (180 degrees)