Regular Polygon Calculator

How many equal sides the polygon has: 3 is a triangle, 5 a pentagon, 6 a hexagon. As n grows the polygon approaches a circle.

Which measurement you know — any one of them fixes the polygon’s size.

• Side length: one edge.
• Perimeter: all n sides together.
• Area: the enclosed surface.
• Apothem: centre to the midpoint of a side.
• Circumradius: centre to a corner.

The numeric size of the chosen quantity. It must be positive; every other measurement is derived from it and n.