Multiple choice

The area of a circle is 38.5 cm2. Find its diameter (in cm).

  1. 7

  2. 14

  3. 10

  4. 20
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A Correct answer
Explanation

Area = pi*r^2 = 38.5. r^2 = 38.5 * 7 / 22 = 12.25. r = 3.5. Diameter = 2*r = 7.

AI explanation

Using the area of a circle formula, 38.5 equals pi times r squared. Substituting pi as 22 over 7 gives r squared equal to 12.25, so the radius r is 3.5 centimeters. The diameter is twice the radius, making it 7 centimeters. The diameter is 7 centimeters.

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