In the fig, AB is parallel to DC and angle C is equal to angle D prove that AD=BC

In the fig, AB is parallel to DC and angle C is equal to angle D prove that AD=BC are (3) below, BA II DF and CA II EC, and BD =
: BF (distance between parallel lines).
BEG and ADCF, LB BAII DE corres. are
BE EC BC- BD = DC