Reckoning / Shape / Regular polygon
Plane figure · Polygons
Regular polygon
n equal sides and equal angles. As n grows it approaches the circle.
Dimensions
Results
area A
circumradius R
interior angle ang
Formulas
n isosceles triangles meet at the centre, each with base s and apex angle 360°/n.
Checked: the A formula agrees with a Monte Carlo measurement of the shape itself, made from its geometric definition, every time the site is built.
Topology lens
Topologically a disc, like every figure here without a hole: Euler characteristic 1. Stretching turns it into a circle, a square or a star. More on the lens.