Question

What is the Law of Cosines?

Answer 1

Given a triangle with sides a, b, c and angles A, B, C (each angle is completely opposite its corresponding side), we have the formulas


c^2 = a^2+b^2 - 2ab*cos(C)

b^2 = a^2+c^2 - 2ac*cos(B)

a^2 = b^2 + c^2 - 2bc*cos(A)


Each formula is independent of the other (ie you can pick which one works best)

Answer 2

\[c^2=a^2+b^2=2ab \cos C\]

Answer 3

These formulas allow you to compute the missing side of a triangle given two sides and an angle that is between the two sides.

Answer 4

Okay thanks guys! I think they are all the "Best Answer" :)