
law of cosines


The law of cosines states that c^{2} = a^{2} + b^{2}  2ab cos C.
It allows us to calculate the third missing side when two sides and the angle in between are known. Similarly, a^{2} = b^{2} + c^{2}  2bc cos A and b^{2} = c^{2} + a^{2}  2ca cos B

