mot be ca lam bang kinh khong co nap dang hinh hop chu nhat co chieu dai 7.5m, chieu rong 5dm,chieu cao 0.7m.biet 1/3the tich be da chua nuoc.tinh dien tich kinh de lam be.hoi muon the tich nuoc trong be bang 85% the tich be thi phai do them vao be bao nhieu lit nuoc