答:∠ABC和∠DFE互余
证明:
∵∠BAC=∠EDF=90°
∴在Rt△ABC和Rt△DEF中,
AC=DF
BC=EF
∴Rt△ABC≌Rt△DEF
∴∠ABC=∠DEF
∴∠ABC+∠DFE=∠DEF+∠DFE=90°
即原题得证.