cosines

(AAS or ASA) or two sides and a non-included angle (SSA). The Law of Cosines The law of cosines generalizes the Pythagorean theorem to non-right triangles. It relates sides and included angles: \[ c^2

\(c\): \[ c^2 = a^2 + b^2 - 2ab \cos C \] Similarly, for the other sides and angles: \[ a^2 = b^2 + c^2 - 2bc \cos A \] \[ b^2 = a^2 + c^2 - 2ac \cos B \] This formula relates the lengths of sides to the cosine of an included angle, enabling the calculation of unknown sides or angl