If a goat is tied on a 50 foot lead to a corner on the outside of a rectangular barn and the barn is 20 feet by 20 feet and the goat can not get into the barn nor is the barn a grazing area, what is the maximum grazing area and show how the maximum grazing area was determined.

A man has a barn that is 20 feet by 10 feet, he tethers a cow to one corner of the outside of the barn using a 50 foot rope. What is the total area that the cow is capable of grazing, show how you arrived at that answer.