∫AD splitting∠ ∠BAC,
∴∠BAD=∠CAD,
∫DE∑AC,
∴∠CAD=∠ADM=∠MAD,
∴DM=AM,
At △AEM and △DBM,
∠BMD=∠AMEDM=AM∠BDM=∠EAM,
∴△AEM≌△DBM(ASA),
∴BM=EM.