let’s say you have 4x feet of fencing, where x is any number. What, in terms of x, should the dimensions of the largest rectangular enclosure be, whose perimeter is 4x feet? What would the area be?

Question

let’s say you have 4x feet of fencing, where x is any number.  What, in terms of x, should the dimensions of the largest rectangular enclosure be, whose perimeter is 4x feet?  What would the area be?