Law relates triangle sides to cosine of one angle. Formula: a² = b² + c² - 2bc·cosA. Generalizes Pythagoras theorem for right triangles
The law of cosines relates triangle sides and angles using the formula: c² = a² + b² - 2abcos(z). The formula can be expressed as c = √(a² + b² - 2abcos(z))
Law of Cosines was introduced by Persian mathematician Jamshid al-Kashi in 15th century. Formula relates triangle sides to their corresponding cosine values. Can be used to find unknown angles or third side from known sides