The back of Tom's property is a creek. Tom would like to enclose a rectangular area, using the creek as one side and fencing for the other three sides, to create a corral. If there is 100 feet of fencing available, what is the maximum possible area of the corral?

? square feet ?

4 answers

length of the 1 side parallel to the creek --- y
length of each of the 2 other sides ---- x

2x + y = 100
y = 100-2x

area = xy
= x(100-2x)
= -2x^2 + 100x

this is modelled by a downwards opening parabola.
Find the vertex and you got the answer.

1200

1250