题目如图,△ABC\triangle ABC△ABC中,AC=8AC=8AC=8,点DDD,EEE分别在BCBCBC,ACACAC上,FFF是BDBDBD的中点.若AB=ADAB=ADAB=AD,EF=ECEF=ECEF=EC,则EFEFEF的长是( )A.333B.444C.555D.666知识点:等腰三角形的性质、直角三角形的性质章节:未标注