SOLUTION: How do I find the radius of a circle if only the area is known. Example: A circle has area 84 sq. in. Find the radius. Thanks! Barb Atwood

Algebra ->  Circles -> SOLUTION: How do I find the radius of a circle if only the area is known. Example: A circle has area 84 sq. in. Find the radius. Thanks! Barb Atwood      Log On


   

Question 821236: How do I find the radius of a circle if only the area is known. Example: A circle has area 84 sq. in. Find the radius.
Thanks!
Barb Atwood
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A circle has area 84 sq. in. Find the radius.
:
You still use the same formula
pi%2Ar%5E2 = 84
Divide both sides by pi
r%5E2 = 84%2Fpi
r%5E2 = 26.738
Find the square root of both sides
r = sqrt%2826.738%29
r = 5.17
:
:
Check on your calc: enter pi%2A5.17%5E2 83.97 ~ 84