Divide the circumference by pi to get the diameter.
Divide the diameter by 2 to get the radius.
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The relationships are usually expressed as
... C = πd . . . . or . . . . C = 2πr
... d = 2r
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Using the first equation, divide by the coefficient of d to find d:
... C/π = d
Using the second equation, divide by the coefficient of r to find r:
... d/2 = r
