The area of the diagonal point triangle - Martin Josefsson In this note we derive a formula for the area of the diagonal point triangle belonging to a cyclic quadrilateral in terms of the sides of the quadrilateral, and prove a characterization of trapezoids. ✪ ✪ ✪ ✪ ✪ Link tải tài liệu: LINK TẢI TÀI LIỆU Theo LTTK Education