How to use the regular polygon calculator
Find area, perimeter and angles of a regular polygon. Enter number of sides, side length in the fields above; the perimeter, area, interior angle, circumradius are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- n — Number of sides
- s — Side length
Worked example
With number of sides = 6, side length = 5, the calculator gives perimeter ≈ 30; area ≈ 64.95191; interior angle ≈ 120 °; circumradius ≈ 5.
Frequently asked questions
What is the formula for the regular polygon calculation?
Perimeter = n × s. Area = n × s × s / (4 × tan(180 / n)). Interior angle (°) = 180 × (n-2) / n. Circumradius = s / (2 × sin(180 / n)). Here n is number of sides, s is side length.
What inputs do I need for the regular polygon calculator?
You need number of sides, side length. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.