 law of cosines

Trigonom.1. a law stating that the square of a side of a plane triangle is equal to the sum of the squares of the other two sides minus twice the product of the other sides multiplied by the cosine of the angle between them.2. a law stating that the cosine of an arc of a spherical triangle equals the sum of the product of the cosines of the other two arcs added to the product of the sines of the other two arcs multiplied by the cosine of the angle between them.
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Generalization of the Pythagorean theorem relating the lengths of the sides of any triangle.If a, b, and c are the lengths of the sides and C is the angle opposite side c, then c^{2} = a^{2} + b^{2} 2ab cos C.* * *
Universalium. 2010.
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Law of cosines — This article is about the law of cosines in Euclidean geometry. For the cosine law of optics, see Lambert s cosine law. Figure 1 – A triangle. The angles α, β, and γ are respectively opposite the sides a, b, and c … Wikipedia
law of cosines — 1. : a law in trigonometry: the square of a side of a plane triangle equals the sum of the squares of the remaining sides minus twice the product of those sides and the cosine of the angle between them 2. : a law in trigonometry: the cosine of an … Useful english dictionary
law of cosines — noun A statement that relates the lengths of the sides of a triangle to the cosine of one of its angles. Syn: cosine formula, cosine rule … Wiktionary
Law of cosines (spherical) — In spherical trigonometry, the law of cosines (also called the cosine rule for sides) is a theorem relating the sides and angles of spherical triangles, analogous to the ordinary law of cosines from plane trigonometry.Given a unit sphere, a… … Wikipedia
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Law of sines — The law of sines (sines law, sine formula, sine rule), in trigonometry, is a statement about any triangle in a plane. Where the sides of the triangle are a , b and c and the angles opposite those sides are A , B and C , then the law of sines… … Wikipedia
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