mklotz: (American) football field = 360 x 160 ft = 57,600 ft^2. Ooops! My bad. I have always thought the field was 100yards long by 50yards wide. No wonder I had trouble making those deep sideline passes! On my errored calculation it would have been a touch at 45000ft^2. My thinking considered only the area between the endzones, which is 48000ft^2
The good thing is, however, this gives us the opportunity to review the pizza effect of radius and/or width on increase in area. Afterall, 3 1/3 yds is only 10'. A 14" pizza is nearly half again as large as a 10" pizza.