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Trigonometry

Law of Cosines Calculator

Finds the third side of a triangle when two sides and the included angle are known, using c = √(a² + b² − 2ab·cos(C)). Essential for solving oblique (non-right) triangles in surveying, navigation, structural engineering, and computer graphics.

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Trigonometry

Law of Cosines Calculator

Calculate the unknown side of any triangle when two sides and the included angle are known, using the Law of Cosines. Essential for navigation, land surveying, and geometry problems.

Fill in the required fields to see your result.

Key differences

Law of Cosines CalculatorLaw of Cosines Calculator
CategoryTrigonometryTrigonometry
Inputs required34
ResultSide C (units)Side C Length (units)
What it doesFinds the third side of a triangle when two sides and the included angle are known, using c = √(a² + b² − 2ab·cos(C)). Essential for solving oblique (non-right) triangles in surveying, navigation, structural engineering, and computer graphics.Calculate the unknown side of any triangle when two sides and the included angle are known, using the Law of Cosines. Essential for navigation, land surveying, and geometry problems.