IMO Shortlist 1993 problem G3
Dodao/la:
arhiva2. travnja 2012. Let triangle
be such that its circumradius is
Let
be the inradius of
and let
be the inradius of the orthic triangle
of triangle
Prove that
%V0
Let triangle $ABC$ be such that its circumradius is $R = 1.$ Let $r$ be the inradius of $ABC$ and let $p$ be the inradius of the orthic triangle $A'B'C'$ of triangle $ABC.$ Prove that $$p \leq 1 - \frac{1}{3 \cdot (1+r)^2}.$$
Izvor: Međunarodna matematička olimpijada, shortlist 1993