An interior angle is the angle between the two adjacent sides of a geometrical shape. An exterior angle is the angle between a side of a geometrical figure and an adjacent side that is extended outwards. The circumradius of a polygon or triangle is the radius of a circumcircle. The latter is a circle that passes through all the vertices. Inradius of a regular polygon is the radius of the incircle which is the largest circle that can fit inside the polygon.

In order to start carrying out calculations, the number of sides should not be less than 3.

When calculating an interior or exterior angle, the answer will always be in degrees.

The units of a circumradius, an inradius and a perimeter are millimeters.

Area is calculated in millimeters squared.

(the number of sides should not be less than 3)

mm

degrees (must be less than 180)

degrees

mm

mm

square mm

mm

Polygon Name = Triangle (or Trigon)

The number of decimal places is preset and is 1. However, the Advanced polygon Calculator is apt of controlling the number of decimal places.