∵△ABD和△BCF为等边三角形∴AB=BD,BC=BF,∠ABD=∠CBF=60°∴∠ABD-∠ABF=∠CBF-∠ABF即∠ABC=∠DBF在△ABC和△DBF中,AB=BD,∠ABC=∠DBF,BC=BF∴△ABC≌△DBF∴AC=DF 而AC=AE∴AE=DF同理可得：AD=EF∴DAEF为平行四...