Work out regular polygon area instantly with clear inputs, formula shown and shareable results.
A regular n-gon divides into n identical isosceles triangles from its centre. Each has base s and height equal to the apothem s/(2·tan(π/n)), so the total area is n·s² / (4·tan(π/n)).
Regular polygon area
A = n·s² / (4·tan(π/n))
Apothem
a = s / (2·tan(π/n))
The polygon approaches a circle of radius equal to the circumradius, and the area tends to πR².
Yes, that is the same formula rearranged and is often easier to remember.