Question 533904
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The circumference of a circle, given the radius, is given by *[tex \Large C\ =\ 2\pi{r}].  So if you are given the circumference you can find the radius by *[tex \Large r\ =\ \frac{C}{2\pi}]


The area of a circle is given by *[tex \Large A\ =\ \pi{r^2}]


Since you start with the circumference, just substitute:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ A\ =\ \pi\left(\frac{C}{2\pi}\right)^2]


Plug in your given number and do the arithmetic.  Hint:  Leave your answer in terms of *[tex \Large \pi] for an exact answer.  If you want a numerical approximation, 3.14 is usually close enough, but 3.14159 can be used if you want greater precision.  *[tex \Large \frac{22}{7}] is only off by 1 in the 3rd decimal place, and *[tex \Large \frac{355}{113}] is good to six places.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
My calculator said it, I believe it, that settles it
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