Joshua’s garden and chicken wire

Joshua has decided to convert part of his back yard into a garden.  He knows from his neighbor’s experience that he needs to fence in the garden to keep the animals out.  At the hardware store, he buys 200 feet of chicken wire.  After he gets home he unrolls the wire, he finds to his surprise that there are many different sizes gardens that he can make with 200 feet of fencing.  He decided that he wants to get the largest garden from 200 feet of fencing.  What are the dimensions of his garden?  I also need to know what if he used “n” feet of chicken wire.