the figure below, ABC is a triangle inscribed in a circle O. Line EBD is
the exterior bisector of the angle ABC (D on AC extended, E on arc AB). A
chord EG cuts AC at X. BC extended meets GD at F. BX extended meets AG at
H. Prove that (1) HF and AD are parallel; (2) Points B, F, G, and H are
This entry contributed by Sumith Peiris, Moratuwa, Sri Lanka.
Geometry problem 1268 in motion.