Law of Cosines Calculator

Solve triangles using the Law of Cosines: c² = a² + b² - 2ab·cos(C)

Side a: Side b: Angle C (°):

Law of Cosines Formula

c² = a² + b² - 2ab·cos(C)

Use this when you know: SAS (two sides + included angle) or SSS (all three sides, to find angles)