证明：延长EB至G使的BG=DF∵BG=DF,AB=AD,∠ABG=∠ADF=90度∴△ABG和△ADF全等,∴AG=AF ∠GAB=∠DAF∵AD平行于BC,所以∠DAF=∠AEB∵AE平分∠BAF∴∠BAE=∠EAF 那么,∠GAB+∠BAE=∠FAF+∠FAD∴∠GAE=∠DAE,∠AEB=...