First you would take the circumference ( 50, 2247) and divide it by pi to get the diameter. You would get 15994.11685. Which I rounded to 15994.12. Then I would divide that by 2, and get 7997.06.
The answer to your question is 405, because look divide 324 by 4 becasue thats how many fifths are being used then multiply the answer which is 81 by 405
