In the figure below, given a triangle
ABC, the incircle of radius r and the contact triangle of area S_{1},
the excircle of radius r_{a} and the contact triangle of
area S_{a}. Prove that: \(\dfrac{S_1}{S_a}=\dfrac{r}{r_a}\).
**
HINTS: **
**1. See Problems
81,
82,
83.** |