A farmer wants to build a fence around hisrectangular field. In addition, he wants todivide it in half with a fence perpendicularto the longer side of the rectangular fieldso that it becomes two smaller squares. Ifthe total length of the fence is 420 feet,what is the length of the shorter side of therectangular field?A.B.C.D.E.30 feet40 feet50 feet60 feet70 feet