证明:1,AB=AD ∠DAF=∠BAF=45° AF=AF
△ADF≅△ABF
2,∠ECB=90-60=30°
CE=CB⇒∠CBE=∠CEB=(180-30)/2=75°
∠ABE=15°=∠ADF
∠AFD=180-(15+45) =120°
3,在FC上截取FH=FD连HD,
∠AFD=120°⇒∠DFH=60°⇒正三角形FHD
⇒FD=DH AD=CD ∠DAF=∠DCH
⇒△DAF≅△DCH=AF=CH⇒CF=AF+DF