⑴ΔABC≌ΔDCB(SSS).
⑵EF平分∠CED.
证明:∵ΔABC≌ΔDCB,
∴∠ECB=∠EBC,
∵EF∥BC,
∴∠CEF=∠ECB,∠DEF=∠EBC,
∴∠DEF=∠CEF,
∴EF平分∠CED.