Masala 2
\( ABC \) uchburchakda \( r \) ichki chizilgan aylana
radiusi, \( r_a \) \( BC \) tomoniga va \( AC, AB \) tomonlari davomiga
urinadigan aylana radiusi bo’lsin. U holda \( \frac{r}{r_a} = \frac{p-a}{p} \) tenglikni isbotlang,
bu yerda \( p \) yarim perimeter.