Multiple choice

The circumference of circle of area $\displaystyle 64\pi $ square units is

  1. $\displaystyle 8\pi $
  2. $\displaystyle 16\pi $
  3. $\displaystyle 32\pi $
  4. $\displaystyle 64\pi $
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B Correct answer
Explanation

Area = pi * r^2 = 64 * pi, so r = 8. Circumference = 2 * pi * r = 16 * pi.

AI explanation

Using the area of a circle formula, area equals pi times the square of the radius, so 64 times pi equals pi times r squared, giving a radius of 8 units. The circumference formula is 2 times pi times the radius, which yields 2 times pi times 8. The circumference is 16 times pi.

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