a) ve nam diem M,N,P,Q,R sao cho ba diem M,N,P thang hang,ba diem N,P,Q thang hang ,con ba diem N,P,R khong thang hang b) ke cac duong thang di qua cac cap diem.Co bao nhieu duong thang,ke ten cac duong thang do c)co bao nhieu doan thang?ke ten cac doan thang do d)ke ten cac tia goc P.Trong cac tia do chi ra hai tia doi nhau ? hai tia trung nhau?