(1)是
(2)延长AD和FE交于点P
CE=DE、∠CEF=∠PED、∠ECF=∠EDP
△ECF和△EDP全等
∴FE=EP
在△AEF和△AEP
AE=AE,∠AEF=∠AEP,EF=EP
∴△AEF≌△AEP
∴AE是∠FAD的角平分线
(3)延长AD和FE交于点P
CE=DE、∠CEF=∠PED、∠ECF=∠EDP(两直线平行,内错角相等)
△ECF和△EDP全等
∴FE=EP
在△AEF和△AEP
AE=AE,∠AEF=∠AEP,EF=EP
∴△AEF≌△AEP
∴AE是∠FAD的角平分线