SOLUTION: A circle has a circumference of 20(pi)meters. Sorry There is no key stroke for pi. Find the radius of the circle. Thanks.

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Question 4156: A circle has a circumference of 20(pi)meters. Sorry There is no key stroke for pi. Find the radius of the circle. Thanks.
Found 2 solutions by Earlsdon, rapaljer:
Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website!
The circumference of a circle is given by: C = piD or C = 2piR Where D and R are the diameter and radius, respectively.
The circumference is given: C = 20pi meters.
2piR = 20pi Divide both sides by pi.
2R = 20 Divide both sides by 2.
R = 10 meters.

Answer by rapaljer(4671) (Show Source):
You can put this solution on YOUR website!
or
Since you need to find th radius, use the second equation, substituting 20 pi for C, the Circumference. The equation now reads:

Divide both sides by 2 pi, in order to solve for r.

When you reduce the fraction, on the left side the 2 and pi divide out, leaving 10 = r. Of course this means that the radius is 10 meters.