A farmer has a rectangular field that is 70 feet by 45 feet as shown below. Instead of keeping the field mowed, he has decided to tether two cows and three goats to posts in the field. The cows will be on the upper side and the goats on the lower side of the field. Each animal has the
ability to eat the grass growing in a circular area swept out if the animal stretches the ropes taught and walks in a circle. There are portions of
these circles, though, the animals cannot reach due to the fence around the field.

Using the diagram below, how much of the field (area) can the animals not reach (i. e. the areas of the field not covered in circles)?

You can print this diagram and measure angles using a protractor. The top two circles are the same size as are the bottom three circles.