∵AC＝CD,∴∠CAD＝∠D∴∠ACB＝∠CAD＋∠D＝2∠CAD∵∠CAD＝∠EBC,∴∠ACB＝2∠EBC∵AB＝AC∴∠ABC＝∠ACB＝2∠EBC∴∠ABE＝∠CBE∴BE平分∠ABE∵∠EAC＝∠EBC＝∠ABE,∠AEF＝∠BEA∴△AEF∽△BEA∴AE：BE＝EF：AE,...