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Regular Polygon Calculator
Enter the number of sides and side length — area and angles update instantly.
Formula
Area = n·s²/(4·tan(π/n)) | Interior angle = (n−2)·180°/n | R = s/(2·sin(π/n))
Example
Hexagon, s = 20 mm → Area = 1039.2 mm², interior angle = 120°, R = 20 mm.
FAQ
What is a regular polygon?
A polygon with all sides equal and all interior angles equal: equilateral triangle, square, regular pentagon, hexagon…
What is the area of a regular hexagon?
For side s: Area = (3√3/2)·s² ≈ 2.598·s². The general n-sided formula also gives this at n = 6.