I labeled the length and width of the new diagram with the new dimensions that I obtained after making the conversion. I made a particular observation that confuses me and that is the statement in the parenthesis indicating that, "it may be cost effective to retain some of the old fencing". Perhaps what's being implied is that it is only necessary to make a rectangle but the fencing that makes up the larger rectangle that houses the smaller rectangle can be retained. Is my conclusion correct? Provided that my assumption is valid then company B is more cost effective and the total cost should be

$578.80 correct? If my conclusion is false then where did my thinking go wrong?

A possible argument is that the area around the smaller rectangle would be impractical. Hence, why the area should be removed. But that would be absurd because the smaller area could just be removed later if it's no longer needed. Wouldn't it make more sense to remove the smaller area later as opposed to adding the larger area again?