In the parallelogram ABCD, e and F are the middle points of the edges AB and CD respectively, BD is the diagonal, and Ag / / DB is made through point a, and CB is crossed It is proved that the quadrilateral debf is rhombic if ∠ g = 90 ° at point G

In the parallelogram ABCD, e and F are the middle points of the edges AB and CD respectively, BD is the diagonal, and Ag / / DB is made through point a, and CB is crossed It is proved that the quadrilateral debf is rhombic if ∠ g = 90 ° at point G

Prove: because the quadrilateral ABCD is a parallelogram, so AB / / DC, ab = CD, AD / / BC, because e and F are the midpoint of AB and CD respectively, so DF = CD / 2, EB = AB / 2, because AB = CD, so DF = EB, because AB / / DC, DF = EB, so the quadrilateral debf is a parallelogram, because AD / / BC, Ag / / BD, angle g = 9