You have 100 feet of fencing to enclose a rectangular plot that borders on a river. If you do not fence the side along the river, find the length and width of the plot that will maximize the area.

Note: The length of the sum of three sides is 100. Let w be the width, find the length in terms of w, setup an equation for the area, then find the vertex (maximum) of your equation. Area of rectangle is length * width.