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The circumference of a circle is the radius times 2 times the irrational number "pi", which is approximately 3.14159. "Irrational" means that the number cannot be calculated as a ratio or fraction, and that the sequence of decimal places never repeats.

So, the circumference of a circle of radius 9 is 56.55.

If you had said that the radius of the circle was 9.0, we could reasonably calculate this to another couple of decimal places, but since the original number wasn't specified to 2 digits of precision, it's not reasonable to try to be more precise in the calculation.

Q: What is the circumference of a circle with the radius of 9?

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If a circle has a circumference of 18pi, the radius is 9.

Doubling the radius doubles the circumference.

A circle with a radius of 4.5 cm has a circumference of 28.27 cm

18 pi

Circumference=2Ï€radius (Ï€ is pi) so... C=2*Ï€*9=18Ï€â‰ˆ56.549

Related questions

A circle with a radius of 9 inches has a circumference of 56.55 inches.

If a circle has a circumference of 18pi, the radius is 9.

Doubling the radius doubles the circumference.

The radius is 1.43

Circumference = 2Π• radius 2Π•9 = (18×Π)"≈ 56.5"

A circle with a radius of 9 inches has a circumference of 56.55 inches and a diameter of 18 inches.

The radius is about 1.432 units.

circumference = 2*pi*9

56.549

If radius of a circle is 9 centimeters the circumference would be: 56.55 cm (r x 2 x Pi = circumference).

The circumference is about 56.55 yards.

A circle with a radius (d/2) of 9 meters has a circumference of 56.5 meters.