Multiple choice

Find the area of a circle whose circumference is $22cm$.

  1. $35.2cm^2$
  2. $38.5cm^2$
  3. $41.7cm^2$
  4. $47.6cm^2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Circumference = 2 * pi * r = 22. r = 22 / (2 * 22/7) = 3.5 cm. Area = pi * r^2 = (22/7) * 3.5 * 3.5 = 38.5 cm^2.

AI explanation

Using the circumference formula C = 2 times pi times r, we set 22 equal to 2 times pi times r. Taking pi as 22/7, the radius calculates to 22 divided by the product of 2 and 22/7, which gives 7/2 cm. Applying the area formula A = pi times r squared, the area is 22/7 multiplied by 49/4 to equal 38.5 square cm.

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