∵AC⊥AB,
∴∠CAB=90°.
∵ED⊥DF,
∴∠EDF=90°.
∴∠CAB=∠FDE,
在Rt△ABC和Rt△DEF中,
∵BC=EF,AC=DF,
∴Rt△ABC≌Rt△DEF,
∴∠BCA=∠DFE.
∵∠CBA+∠BCA=90°,
∴∠ABC+∠DFE=90°.
∵AC⊥AB,
∴∠CAB=90°.
∵ED⊥DF,
∴∠EDF=90°.
∴∠CAB=∠FDE,
在Rt△ABC和Rt△DEF中,
∵BC=EF,AC=DF,
∴Rt△ABC≌Rt△DEF,
∴∠BCA=∠DFE.
∵∠CBA+∠BCA=90°,
∴∠ABC+∠DFE=90°.