Let AB and ED intersect at g point,

∫△ABC and△△△ AED are equilateral△,

∴∠B=∠C=60，BC=CA，FB=DC，

∴△FBC≌△DCA﹙SAS﹚，

∴FC=DA=ED,∠BCF=∠CAD，

And ∠ CAD+∠ DAB = 60 = ∠ DAB+∠ EAB,

∴∠CAD=∠EAB，

Investigate the sum of internal angles of △AEG and △DBG,

∠AEG =∠b = 60 ,∠ega=∠dgb,∴∠eab=∠gdb，

∴∠GDB=∠FCB，

∴ED∥FC，

∴ Quadrilateral DCFE is a parallelogram. A group of parallelograms with parallel and equal opposite sides are parallelograms.

∴EF∥DC, namely ef∨BC.