Cho tam giac ABC vuong tai A [AB<AC]. Tren canh BC lay diem M sao cho BM =BA .Goi Ela trung diem cua AM ,K la giao diem cua BE va AC. a] Chung minh tam giac ABE=MBE . b] Chung minh KM vuong goc BC. c] Qua M ke duong thang song song voi AC cat BK tai F . Tren doan KC lay diem Q sao cho KQ =MF .Chung minh ABK = QMC.