Law of Cosines

The Law of Cosines is a formula in geometry that relates the lengths of sides of a triangle to the cosine of one of its angles. It helps find an unknown side or angle when you know the other sides and angles. Specifically, for a triangle with sides a, b, and c, and the angle opposite side c being γ, the law states: \[ c^2 = a^2 + b^2 - 2ab \cosγ \] It generalizes the Pythagorean theorem for non-right triangles, providing a precise way to solve triangles when you have partial information.