Regular Polygon Area Calculator

Compute the area of a regular polygon from the number of sides and the side length, plus perimeter, apothem, circumradius and interior angle.

Input

Enter the number of sides and the side length to compute the area of a regular polygon along with its perimeter, apothem, circumradius and interior angle.

Number of sides n

Side length a

Result

Area

259.807621

Perimeter

Apothem (inradius)

8.660254

Circumradius

Interior angle

120°

Lengths use the same unit as the input and the area is in that unit squared.

How it works

For a regular polygon with n sides and side length a, the area is area = (n × a²) / (4 × tan(π/n)).
The perimeter is n × a and each interior angle is (n − 2) × 180 ÷ n degrees.
The apothem (inradius) is a ÷ (2 × tan(π/n)) and the circumradius is a ÷ (2 × sin(π/n)).
The number of sides must be an integer of 3 or more, and the side length must be positive.
Lengths use the same unit as the input and the area is in that unit squared.

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