In a circle, this distance equals the radius minus the sagitta of a chord, which equals the distance from the center of the circle to the midpoint of 
In a circle, this distance equals the radius minus the sagitta of a chord, which equals the distance from the center of the circle to the midpoint of that chord. For other shapes, this equals the side length divided by twice the tangent of the quantity pi over n, where n is the number of sides, so, for example, it equals the side length times root three over two for a regular hexagon. For any regular polygon, this distance is twice the area divided by the perimeter. Contrasted with the radius of a polygon, name this distance, or segment, from the center of a regular polygon to the midpoint of one of its edges.
In a circle, this distance equals the radius minus the sagitta of a chord, which equals the distance from the center of the circle to the midpoint of that chord.
{apothem} [accept {inradius}; do not accept or prompt on “{radius}”]