You will build two identical rectangular enclosures next to a each other, sharing a side. You have a total of 324 324 feet of fence to use. Find the dimensions of each pen such that you can enclose the maximum possible area. One approach is to let x represent the length of fencing that the two pens share, and write a formula for a function of x that outputs the total area of the enclosures. Then find its vertex and interpret it. (Use ft for feet, and ft^2 for square feet.)