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Sine area formula

Use sides a and b around angle C

Area = 1/2 ab x sin(C)
heightheightheightABCabcArea = 1/2 x base x heightbase b, height a sin(C)base c, height b sin(A)base a, height c sin(B)choose any included angle

Sides a and b meet at angle C. If b is the base, the height is the part of side a that rises above b, which is a x sin(C).