A rancher has 400
meters of fencing. He will fence a rectangular corral next to a cliff. So, he
will use all 400 meters to make just 3 sides of the rectangle. He wants to make
a corral that will hold as many cattle as possible, so he wants the corral to
contain the largest area possible. How long and how wide should he make the
corral?
Your diagram (see an example by clicking here):