"cyclic" is referenced in the pages listed below.
The sum of the products of opposite sides of an inscribed (cyclic) quadrilateral are equal to the product of its diagonals.
A formula for finding the area of an inscribed (cyclic) quadrilateral when you know the lengths of the four sides.
Definition and properties of a quadrilateral inscribed in a circle. Sometimes called a cyclic quadrilateral.
Opposite pairs of interior angles of an inscribed (cyclic) quadrilateral are supplementary
(C) 2011 Copyright Math Open Reference. All rights reserved