Calculate the area, perimeter, and angles of a regular seven-sided polygon (heptagon).
Dimensions
Heptagon Properties
90.85
Area (A)
Geometric properties of a regular heptagon.
Perimeter (P)35.00
Interior Angle128.57°
Regular Heptagon
About this calculator
What is a Heptagon?
A heptagon is a seven-sided polygon. In a regular heptagon, all sides are of equal length and all interior angles are equal. It is also sometimes known as a septagon.
💡
Pro Tips
The sum of interior angles in any heptagon is exactly 900°.
A regular heptagon is not constructible with a compass and unmarked straightedge (Neusis construction is required).
The British 20p and 50p coins are technically 'reuleaux heptagons'—equidistant curves based on a regular heptagon.
!
Fun Facts
"There are no naturally occurring 7-fold crystals because they cannot tile a 3D space perfectly."
"In many cultures, seven is considered a lucky or mystical number, adding intrigue to this rare geometric shape."
"The heptagon is the smallest regular polygon that cannot be constructed by the traditional Greek method of circle and line."
