Question

正方形ABCD．左上角是A,左下角是B,右下角是C,右上角是D

Answer 1

辅助线：延长CB到G,使BG=DF

∵正方形ABCD,AB=AD,AB⊥BC,AD⊥DC

∴△ABG全等于△ADF

∴∠GAB=∠FAD,∠AGB=∠AFD

∵AF平分角EAD

∴∠GAB=∠FAE

∵AB‖CD

∴∠AFD=∠FAB

∴∠GAB =∠FAB=∠GAE

∴△AEG为等腰△,AE=EG=BE+BG=BE+DF