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Formula Law of Cosine for a General Triangle Third side length    First side length    Second side length    Angle

Formula
Formula: Law of Cosine for a General Triangle
Allgemeines Dreieck mit Winkeln und Kanten

Third side length

Unit
The length of the third side of the triangle.

First side length

Unit
The length of the first side of the triangle.

Second side length

Unit
The length of the second side of the triangle.

Angle

Unit
This angle is opposite the side \( c \). So the angle between the sides \( a \) and \( b \). If \( \gamma ~=~ 90^{\circ} \), the cosine term is dropped and the Pythagorean theorem remains.