As shown in the figure, in the parallelogram ABCD, e is the midpoint of CD, and the extension line of be and ad intersects at point F Million urgent A. still have half an hour to hand in homework a. a a... will add ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD

As shown in the figure, in the parallelogram ABCD, e is the midpoint of CD, and the extension line of be and ad intersects at point F Million urgent A. still have half an hour to hand in homework a. a a... will add ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD ADD

prove:
In the parallelogram ABCD, AB is parallel to CD,
So angle FDE = angle fab, angle fed = angle FBA
So triangle ABF is similar to triangle def
There are DF: AF = de: ab
Because e is the midpoint of CD, de = (1 / 2) CD = (1 / 2) ab
So AF = 2DF, ad = DF
Similarly, be = EF