Problem

[103]

\(\qquad\)Let \(ABC\) be an acute-angled triangle with \(AB \ne AC\). The circle with diameter \(BC\) intersects the sides \(AB\) and \(AC\) at \(M\) and \(N\) respectively. Denote by \(O\) the midpoint of the side \(BC\). The bisectors of the angles \(\angle BAC\) and \(\angle MON\) intersect at \(R\). \(\\\qquad\)Prove that the circumcircles of the triangles \(BMR\) and \(CNR\) have a common point lying on the side \(BC\).

Solution

Attributes Олімпіадна
Source International Mathematical Olympiad
Year 2004
Number 1
Difficulty 10.0
Themes Геометрія