The law of sines is useful for calculating one side or angle of any triangle, when five of the six angles and sides are known.
( s i n A a ) = ( s i n B b ) = ( s i n C c ) {\displaystyle \left({\frac {sin{A}}{a}}\right)=\left({\frac {sin{B}}{b}}\right)=\left({\frac {sin{C}}{c}}\right)}