mot thua ruong hinh chu nhat co chieu rong 600m,chieu dai gap 3 lan chieu rong
a] HOI dien tich thua ruong do duoc bao nhieu hec ta
b] nguoi ta cay lua tren thua ruong , biet rang cu 100 met vuong thu hoach duoc 62 kg thoc . hoi tren ca thua ruong thu hoach duoc bao nhieu tan thoc