Find the mistake made in the following proof. Explain why you think your colleague made this mistake. Given: AB∣∣∣∣ED and AB≅ED

Prove: ΔABF≅ΔDEF

Proof:

It is given that AB∣∣∣∣ED so angle ∠DEB is congruent to angle ∠ABE because parallel lines form congruent alternate interior angles with a transversal. It is also given that AB is congruent to ED and angle ∠AFB is congruent to angle ∠DFE because they are vertical angles and vertical angles are congruent. So, ΔABF is congruent to ΔDEF by ASA.