The perpendicular from the center to one of the sides of a regular polygon.
the perpendicular distance from the centre of a regular polygon to a side
in a regular polygon, the perpendicular distance from the center to a side; in a circle with a chord, the distance from the midpoint of a chord to the circle's center
of a regular polygon A perpendicular segment from the center of the polygon' s circumscribed circle to a side of the polygon (Lesson 9.4).
Perpendicular line from the center of a regular polygon to any one of its sides.
An apothem of a geometric figure is the perpendicular line segment, usually from the center, to an edge, or the length thereof.