In
geometry, a
cyclic quadrilateral is a
quadrilateral whose
vertices[?] are all lie on a single
circle. The vertices are said to be
concyclic[?].
- Opposite angles of a cyclic quadrilateral add up to <math>\pi</math>.
- The area of a cyclic quadrilateral is given by Brahmagupta's formula.
- The area of a cyclic quadrilateral is maximal among all quadrilaterals having the same (multi)set of side lengths.