ɪnˈreɪdiəs

Definitions

1. noun

The radius of the circle that is tangent to all the sides of a polygon or to all the sides of a polyhedron, and is used to calculate the area or volume of the polygon or polyhedron.

“The inradius of the regular hexagon is used to find its area.”

2. noun

In geometry, the distance from the center of a shape to its incircle, which is the largest circle that fits inside the shape and touches its sides.

“The inradius of the triangle is the distance from the circumcenter to the incircle.”