Here's the gist and you can then elaborate:
Proof:
BC = EC, AC = DC (this is given)
angle BCA = angle ECD (vertical angles)
Therefore triangle BCA = triangle ECD (by the side-angle-side theorem).
So therefore BA = ED ( by Congruent Parts of Congruent Triangles are Congruent)
This is not a paragraph proof. You will need to add a little bit more of explanation.