Proof: from folding, we know that AD=FD, AE=FE,
∴D and E are both on the perpendicular of AF,
∴DE vertically divides AF,
∴DE⊥AF。
⑵AD=DF,AE=CE .∠A=∠DFE,
∠ Ade =∠FDE,
AED= federal reserve.