Difference between revisions of "Bretschneider's formula"

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It can be derived with [[vector]] [[geometry]].
 
It can be derived with [[vector]] [[geometry]].
  
==The Proof==
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==Proof==
 
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''This article needs a proof. Please help us out by [http://www.artofproblemsolving.com/Wiki/index.php?title=Bretschneider%27s_formula&action=edit adding one]''.
 
==See Also==
 
==See Also==
 
* [[Brahmagupta's formula]]
 
* [[Brahmagupta's formula]]
 
* [[Geometry]]
 
* [[Geometry]]
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[[Category:Geometry]]
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[[Category:Theorems]]

Revision as of 18:04, 7 October 2007

Suppose we have a quadrilateral with edges of length $a,b,c,d$ (in that order) and diagonals of length $p, q$. Bretschneider's formula states that the area $[ABCD]=\frac{1}{4}*\sqrt{4p^2q^2-(b^2+d^2-a^2-c^2)^2}$.

It can be derived with vector geometry.

Proof

This article needs a proof. Please help us out by adding one.

See Also

This article is a stub. Help us out by expanding it.