解：?$ (1)$?如圖所示
?$ (2)$?結(jié)論：?$DF $?平分?$∠CDA，$?理由如下：
∵?$∠A=∠C=90°$?
∴?$∠ABC+∠ADC=180°$?
∵?$DF//BE$?
∴?$∠DFC=∠CBE$?
∵?$BE$?平分?$∠ABC$?
∴?$∠ABC=2∠CBE=2∠CFD$?
∵?$∠CFD+∠CDF=90°$?
∴?$2∠DFC+2∠CDF=180°$?
∴?$∠ABC+2∠CDF=180°$?
∴?$∠ADC=2∠CDF$?
∴?$DF $?平分?$∠CDA$?
