Heptagon Definition | Polygon Shape |

Heptagon Definition
A heptagon is also known as a septagon

A heptagon is a 7 sided polygon
A regular polygon has equal length sides with equal angles between each side.
Circles and shapes that include curves are not polygons

A regular heptagon has 7 equal sides and 7 equal angles.
The general formula for the sum of all interior angles of a polygon
(n-2)180 n = the number of sides
900 /7 = 128.57 degrees
The degree measure of the interior angles equals sum of all interior angles divided by the number of sides

A Heptagon has 14 diagonals
If you look closely they are the red lines
You can Find the number of diagonals by using,

n (n - 3) / 2
n = number vertices

You can find the measure of the central angle by dividing 360 degrees by 7 which equals 51.43 degrees

Area
If the apothem is known area = ½ perimeter times apothem

If you do not know the Apothem length then not find the apothem using
Apothem = side/ 2Tan ( 180/number sides)
Once you know Apothem then use

½ Perimeter times Apothem

Heptagons can also be irregular which means the shape does not have equal sides or angles
So there you go, a 7 sided polygon the heptagon