Problems(1)
Let D be a point on the circumcircle of some triangle ABC. Let E,F be points on AC, AB, respectively, such that A,D,E,F are concyclic. Let M be the midpoint of BC. Show that if DM, BE, CF are concurrent, then either BE∩CF is on the circle ADEF, or EF is parallel to BC.proposed by USJL geometryconcurrency