cyclic quadrilateral

Cyclic quadrilateralMathworldPlanetmath.
A quadrilateralMathworldPlanetmath is cyclic when its four vertices lie on a circle.

A necessary and sufficient condition for a quadrilateral to be cyclic, is that the sum of a pair of opposite angles be equal to 180.

One of the main results about these quadrilaterals is Ptolemy’s theorem.

Also, from all the quadrilaterals with given sides p,q,r,s, the one that is cyclic has the greatest area. If the four sides of a cyclic quadrilateral are known, the area can be found using Brahmagupta’s formula

Title cyclic quadrilateral
Canonical name CyclicQuadrilateral
Date of creation 2013-03-22 11:44:16
Last modified on 2013-03-22 11:44:16
Owner drini (3)
Last modified by drini (3)
Numerical id 12
Author drini (3)
Entry type Definition
Classification msc 51-00
Classification msc 81R50
Classification msc 81P05
Classification msc 81Q05
Classification msc 81-00
Synonym cyclic
Related topic OrthicTriangle
Related topic PtolemysTheorem
Related topic ProofOfPtolemysTheorem
Related topic CircumcircleMathworldPlanetmath
Related topic Quadrilateral