Multiple choice

The circumference and area of a circle of diameter 91 cm are, respectively

  1. $367\, cm,\, 4986.5\, cm^2$
  2. $442\, cm,\,6166.5\, cm^2$
  3. $286\, cm,\, 6506.5\, cm^2$
  4. $456\, cm,\, 5466.5\, cm^2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Diameter = 91, radius = 45.5. Circumference = pi * d = 3.14159 * 91 = 285.88 (approx 286). Area = pi * r^2 = 3.14159 * (45.5)^2 = 6503.8 (approx 6506.5).

AI explanation

The radius is half the diameter, which is 91 divided by 2 or 45.5 cm. The circumference is pi times diameter, so 22 divided by 7 times 91 equals 286 cm. The area is pi times the square of the radius, so 22 divided by 7 times 45.5 times 45.5 equals 6506.5 square cm.

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