In a triangle, the name given to this relation:
\(\dfrac{\textrm{tan}\dfrac{\textrm{A}+\textrm{B}}{2}}{\textrm{tan}\dfrac{\textrm{A}-\textrm{B}}{2}} = \dfrac{\dfrac{a + b}{2}}{\dfrac{a\space–\space b}{2}}\)
where A and B are the measures of the angles opposite the sides of measures \(a\) and \(b\) of any triangle.
