3 ban an ,bac,cuong dung co dinh mot cay sao thang dung roi danh dau chieu cao cua cac ban len do boi ba diem .cuong dat ten cho cac diem do theo thu tu tu duoi len la a,b,c va giai thich la diem a ung voi chieu cao cua ban an b ung voi chieu cao cua ban bac va c ung voi chieu cao cua ban cuong biet rang ban an cao 150 cm,ban bac cao 153 cm ban cuong cao 148 cm.theo em,cuong giai thich nhu the co dung khong hoi neu khong phai sua nhu the nao cho dung.