Heptagon

A heptagon, also referred to as a septagon or 7-gon is a shape with 7 sides and 7 corners.

All sides of a regular heptagon are the same length. Each corner is about 128.6°. All corners added together are equal to 900°.

The amount of space a regular heptagon takes up is

${\displaystyle A={\frac {7}{4}}a^{2}\cot {\frac {\pi }{7}}\simeq 3.634a^{2}.}$

a is the length of one of its sides.