Email Print Law of Cosines Written by Jerry Ratzlaff on 24 January 2016. Posted in Trigonometry An equation relating to cosine of an interior angle and the lengths of the sides of a triangle. Law of Cosines Formula \(\large{ c^2= a^2+b^2-2ab* cosC }\) \(\large{ a^2= b^2+c^2-2ab* cosA }\) \(\large{ b^2= a^2+c^2-2ab* cosB }\)
An equation relating to cosine of an interior angle and the lengths of the sides of a triangle.