Then there is ∠EHB=∠BCA, ∠ HED = ∠ F.
AB = AC
∴∠B=∠BCA,
∴∠EHB=∠B
∴EH=EB
And EB=CF
∴EH=CF
∠EDH=∠FDC again
∠HED=∠F
∴△EDH is equal to △ △FDC.
So ED=FD