Properties of Triangles

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BC = a, AC = b and AB = c

Area of triangle is denoted by Δ and the radius of the circumcircle by R.

Sine Rule :

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Cosine Rule :

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Projection Formulae :

a = b cos C + c cos B

b = c cos A + a cos C

c = a cos B + b cos A

Tangent Rule :

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Half Angle:

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