如图,BC‖EF,AC‖DF,AE=DB,求证;BC=EF.
∵BC∥EF,∴∠CBA=∠FEB,
∵AC∥DF,∴∠A=∠D,
∵AE=DB,∴AD+BE=BD+BE,即AB=DE,
∴ΔABC≌ΔDEF,
∴BC=EF.