Difference between revisions of "Ptolemy's Inequality"

 
m (Ptolemy inequality moved to Ptolemy's Inequality: fixed name)
(No difference)

Revision as of 14:25, 20 June 2006

Ptolemy's inequality for a convex quadrilateral ABCD states that AB·CD + BC·DA ≥ AC·BD with equality iff ABCD is a cyclic quadrilateral.