IMO Shortlist 1978 problem 12
Dodao/la: arhiva2. travnja 2012.
In a triangle
A circle which is internally tangent with the circumscribed circle of the triangle is also tangent to the sides
in the points
Prove that the midpoint of
is the center of the inscribed circle of the triangle
Izvor: Međunarodna matematička olimpijada, shortlist 1978