SOLUTION: What is the exact area of a circle with a diameter of 21 inches? Please help if you can! Thank you.

Algebra ->  Circles -> SOLUTION: What is the exact area of a circle with a diameter of 21 inches? Please help if you can! Thank you.      Log On


   

Question 480322: What is the exact area of a circle with a diameter of 21 inches? Please help if you can! Thank you.
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
A=pi%2Ar%5E2

The radius r is 1%2F2 the diameter, which is 21,
so the radius r = expr%281%2F2%2921=21%2F2

A=pi%2A%2821%2F2%29%5E2

A=pi%2A%2821%5E2%2F2%5E2%29

A=pi%2A%28441%2F4%29

A=%28pi%2F1%29%2A%28441%2F4%29


A=441pi%2F4