Given an acute triangle ABC with AC>BC and the circumcenter of triangle ABC is O. The altitude of triangle ABC from C intersects AB and the circumcircle at D and E, respectively. A line which passed through O which is parallel to AB intersects AC at F. Show that the line CO, the line which passed through F and perpendicular to AC, and the line which passed through E and parallel with DO are concurrent.Fajar Yuliawan, Bandung geometrycircumcircleprojective geometrygeometry unsolved