The point of concurrence of the four maltitudes of a cyclic quadrilateral. Let M_(A C) and M_(B D) be the midpoints of the diagonals of a cyclic quadrilateral A B C D, and let P be the intersection of the diagonals. Then the orthocenter of triangle Δ P M_(A C) M_(B D) is the anticenter T of A B C D.

cyclic quadrilateral | maltitude