cho tam giac ABC, diem M la trung diem cua canh CB. Tren tia doi cua tia MA lay diem E sao cho ME=MA a) chung minh tam giac AMC= tam giac EMB, b) chung minh AB//CE, c) goi I la mot diem tren canh AC, K la mot diem tren doan thang EB sao cho AI=EK. Chung minh ba diem I,M,K thang hang