Mot cai thung nhom co dang hinh hop chu nhat. Day la mot hinh vuong co canh 5dm va chieu cao 3.5dm.a.Muon lam cai thung nhu the va ko co nap can bao nhieu m2 nhom (cac mep han ko dang ke) .b.Thung chua duoc nhieu nhat bao nhieu lit nuoc? (1dm3 = 1lit)