Multiple choice

What is the approximate circumference of a circle whose area is $7.2$?

  1. $9.51$
  2. $9.15$
  3. $7.20$
  4. $4.13$
  5. $3.14$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Area = pi * r^2 = 7.2. r^2 = 7.2 / pi approx 2.29. r = sqrt(2.29) approx 1.513. Circumference = 2 * pi * r = 2 * pi * 1.513 approx 9.506. Option A is the closest.

AI explanation

Using the area of a circle formula, pi times radius squared equals 7.2, so the radius squared is 7.2 divided by 3.14, which is approximately 2.293. The radius is the square root of 2.293, approximately 1.514. The circumference is found by multiplying 2, pi, and the radius together, giving 2 times 3.14 times 1.514, which results in an approximate circumference of 9.51.

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