Because the triangle ABD is equilateral, AB=DB angle ABD=60 degrees.

Because the triangle BCE is equilateral, BE=BC angle EBC=60 degrees.

Therefore, the angle ABD= the angle EBC is the same as the angle DBE, that is, the angle ABE= the angle DBC.

Because AB=DB

Angel Abbe = Angel ·DBC

BE=BC

So consistent

So AE=DC