A heptagon is a 7-sided polygon with 7 interior angles that sum to 900 °. The name heptagon derives from the Greek words hepta- for seven and -gon for sides. A heptagon is also called a 7-gon or septagon ( septa- is Latin for seven).
The formula for calculating the sum of the interior angles of a regular polygon is: (n - 2) × 180°. Where n is number of sides.
