IMO 2011 Shortlist G8

Let ABC be an acute triangle with circumcircle ω. Let t be a tangent line to ω. Let ta, tb, and tc be the lines obtained...

IMO 2011 Shortlist G8

Category: Geometry

Problem

Let ABC be an acute triangle with circumcircle ω. Let t be a tangent line to ω. Let ta, tb, and tc be the lines obtained by reflecting t in the lines BC, CA, and AB, respectively. Show that the circumcircle of the triangle determined by the lines ta, tb, and tc is tangent to the circle ω.