Ptolemy's Theorem: Difference between revisions
Created page |
→Definition: added links to other topics |
||
| Line 3: | Line 3: | ||
=== Definition === | === Definition === | ||
Given a cyclic quadrilateral <math>ABCD</math> with side lengths <math>{a},{b},{c},{d}</math> and diagonals <math>{e},{f}</math>: | Given a [[cyclic quadrilateral]] <math>ABCD</math> with side lengths <math>{a},{b},{c},{d}</math> and [[diagonals]] <math>{e},{f}</math>: | ||
<math>ac+bd=ef</math> | <math>ac+bd=ef</math> | ||
Revision as of 13:08, 18 June 2006
Ptolemy's theorem gives a relationship between the side lengths and the diagonals of a cyclic quadrilateral; it is the equality case of the Ptolemy inequality.
Definition
Given a cyclic quadrilateral
with side lengths
and diagonals
: