37 . A rectangular region with area 3200 square feet is to be enclosed within a fence . The two sides which in north - south will use fencing materials costing $1 .10 per foot , while the other two sides require fencing materials which cost $2 00 per foot Find the dimensions of the region which gives the small est material cost ANS BO ft ( north - south fence ) by 40 it ( east - west fence ) PIS