law of sines

law of sines

1. (trigonometry) A statement that relates the lengths of the sides of a triangle to the sines of its angles.

Let a, b, and c be the lengths of the sides of a triangle opposite angles A, B, and C. The law of sines states that ${\displaystyle {\frac {a}{\sin {A}}}\,=\,{\frac {b}{\sin {B}}}\,=\,{\frac {c}{\sin {C}}}\,=\,2R}$, where R is the radius of the triangle's circumcircle.

• sine formula
• sine law
• sine rule

• law of cosines