Multiple choice

If the area of a circle is 15400 $cm^{2}$, then its circumference is

  1. 449 cm

  2. 440 cm

  3. 450 cm

  4. 460 cm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Area = pi * r^2 = 15400. Using pi = 22/7, r^2 = 15400 * 7 / 22 = 4900, so r = 70. Circumference = 2 * pi * r = 2 * (22/7) * 70 = 440 cm.

AI explanation

Using the area formula, 15400 = (22 / 7) * r^2, which gives r^2 = 15400 * 7 / 22 = 4900. Taking the square root results in r = 70 cm. Applying the circumference formula, 2 * pi * r = 2 * (22 / 7) * 70 = 440 cm. The result is 440 cm.

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