Mot thua ruong hinh chu nhat co chu vi 840m va chieu rong ban 1/2 chieu dai.
a Tim chieu dai chieu rong cua thua ruong
B Nguoi ta cay lua o thua ruong di , tinh ra cu 100 met vuong thu hoach duoc 50 kg thoc . Hoi da thu hoach duoc o thua ruong do bao nhieu ta thoc??