A gardener has 720 feet of fencing to fence in a rectangular garden. One side of the garden is bordered by a river and so it does not need any fencing.What dimensions would guarantee that the garden has the greatest possible area?

Answer 1

as always, divide the fencing so that it is evenly split between lengths and widths. You only have one length, because of the river. So, the maximum area is when the garden is 360ft x 180ft

extra credit: show that this is true.