37th Austrian Mathematical Olympiad 2006
Source: round1, problem3 - triangles, cirumcircles and tangent lines
February 10, 2009
geometrycircumcircleangle bisectorexterior anglegeometry unsolved
Problem Statement
In a non isosceles triangle let be the angle bisector of the exterior angle at . Let be the point of intersection of with the extension of . Let be the circumcircle of the triangle and analogy the circumcircle of the triangle . Let be the tangent line to in A and the tangent line to in B. Let be the point of intersection of and .
Given are the points and . Determine the set of points P\equal{}P(C ) over all points , so that is a non isosceles, acute-angled triangle.