In △ ABC, E.F AB.CB G. h is fed to two points on AC, and Ag = GH = HC EG.FH Intersection at point D. proof: a quadrilateral ABCD is a parallelogram

In △ ABC, E.F AB.CB G. h is fed to two points on AC, and Ag = GH = HC EG.FH Intersection at point D. proof: a quadrilateral ABCD is a parallelogram

It is proved that BG, BH and BD are connected to AC in o respectively
∵ e is the midpoint of AB, Ag = GH
The EG is a median line of △ ABH
That is GD / / BH
Similarly, BG / / DH can be proved
The quadrilateral bhdg is a parallelogram
  ∴ BO=OD,GO=OH.
And ∵ Ag = HC ∵ Ag + go = HC + Oh
That is Ao = OC and Bo = OD (proved)
A quadrilateral ABCD is a parallelogram