nice one
Source: iran2004(geo exam)
September 10, 2004
geometrycircumcircleprojective geometrymodular arithmeticEulergeometry proposed
Problem Statement
assume that ABC is acute traingle and AA' is median we extend it until it meets circumcircle at A". let be a diameter of the circumcircle. the pependicular from A' to meets the tangent to circumcircle at A" in the point ; we define similary . prove that are one a line.