∵AF平分∠DAB
∴∠BAF=∠DAB/2
∵∠FCE=∠CEB
∴CD∥AB (内错角相等,两直线平行)
∴∠DFA=∠BAF (两直线平行,内错角相等)
∴∠DFA=∠DAB/2
∵CE平分∠DCB
∴∠DCE=∠DCB/2
∵∠DAB=∠DCB
∴∠DFA=∠DCE
∴AF∥CE (同位角相等,两直线平行)
∵AF平分∠DAB
∴∠BAF=∠DAB/2
∵∠FCE=∠CEB
∴CD∥AB (内错角相等,两直线平行)
∴∠DFA=∠BAF (两直线平行,内错角相等)
∴∠DFA=∠DAB/2
∵CE平分∠DCB
∴∠DCE=∠DCB/2
∵∠DAB=∠DCB
∴∠DFA=∠DCE
∴AF∥CE (同位角相等,两直线平行)