It is proved that∵ quadrilateral ABCD is a parallelogram.

∴AD=BC,AD‖BE

AD‖BE and AC‖DE.

A quadrilateral is a parallelogram.

∴AD=CE,∵AD=BC

∴BC=CE,∵EF⊥AB

∴∠EFB=90

∴CE=BC=CF

∴AD=CF