Law of cosines: Difference between revisions
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imported>David E. Volk (New page: The law of cosines is a useful identity for determining an angle or the length of one side of a triangle, when given two angles and three lenghts or three angles and two lengths, respectiv...) |
imported>David E. Volk No edit summary |
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<math> c^2 = \left(a^2 + b^2\right) - \left(2ab\right)cos(C) </math> | <math> c^2 = \left(a^2 + b^2\right) - \left(2ab\right)cos(C) </math> | ||
[[Image:Triangle.jpg|center|frame|Triangle]] | |||
Revision as of 17:28, 3 October 2007
The law of cosines is a useful identity for determining an angle or the length of one side of a triangle, when given two angles and three lenghts or three angles and two lengths, respectively. When dealing with a right triangle, the law of cosines reduces to the Pythagorean theorem because the cos(90) is zero. To determine the areas of triangles, see the Law of sines.
Triangle