Rule

The Law of Sines

The Law of Sines is an equation relating the angles and the sides of a triangle. For a given triangle the ratio between the sine value of an angle and the length of its opposite side is constant.

$\dfrac{\sin(A)}{a}=\dfrac{\sin(B)}{b}=\dfrac{\sin(C)}{c}$

$A,$ $B,$ and $C$ are the measures of the angles of the triangle, while $a,$ $b,$ and $c$ are the opposite sides of each angle, respectively.

An alternative way to write the Law of Sines is as a ratio between the side and the sine value of its opposite angle.

$\dfrac{a}{\sin(A)}=\dfrac{b}{\sin(B)}=\dfrac{c}{\sin(C)}$