SOLUTION: The circumference of circle II is 4 feet longer than the circumference of circle I. How many feet longer is the radius of circle II than the radius of circle I?

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Question 493662: The circumference of circle II is 4 feet longer than the circumference of circle I. How many feet longer is the radius of circle II than the radius of circle I?

Answer by stanbon(75887) (Show Source):
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The circumference of circle II is 4 feet longer than the circumference of circle I. How many feet longer is the radius of circle II than the radius of circle I?
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Formula: Circumference = (pi)(diameter) = (pi)(2r)
So radius = Circumference/(2pi)
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Circumference of circle I = pi*(2r)
radius of Circle I = r = C/(2pi)
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Circumference of circle II = 2(pi)r + 4
radius of Circle II = R = [2(pi)r+4]/(2pi) = [(pi)r +2]/pi = r + (2/pi)
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Circle II's radius is [2/pi] ft longer
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Cheers,
Stan H.
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