Multiple choice

The area of a circle is $394.24$ $cm^2$. Then the circumference of the circle is

  1. 116 cm.

  2. 70.4cm.

  3. 100cm.

  4. 88cm.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given area = pi * r^2 = 394.24. Using pi = 3.14, r^2 = 125.55, so r = 11.2. Circumference = 2 * pi * r = 2 * 3.14 * 11.2 = 70.336, which rounds to 70.4.

AI explanation

The radius squared equals the area divided by pi, which is 394.24 divided by 3.14, giving 125.64. The square root of 125.64 is 11.2 cm. The circumference equals 2 times pi times radius, so 2 times 3.14 times 11.2 gives 70.4 cm.