设:AD和BE的交点为G
∵BE平分∠ABC,EF⊥BC,AE⊥AB
∴连接FG,且FG所在的直线垂直于AB
即:FG∥AC
且:FG = EF,∠C = ∠BFG
∵∠ADC = ∠BAC = 90°
∴△ABC≌△DGF
∴FG/DF = EF/DF = BC/AC
设:AD和BE的交点为G
∵BE平分∠ABC,EF⊥BC,AE⊥AB
∴连接FG,且FG所在的直线垂直于AB
即:FG∥AC
且:FG = EF,∠C = ∠BFG
∵∠ADC = ∠BAC = 90°
∴△ABC≌△DGF
∴FG/DF = EF/DF = BC/AC