how do you find the circumference of a circle

To find the circumference of a circle, you use one of the following formulas depending on the information you have:

• If you know the radius rrr, the circumference CCC is calculated as:

C=2πrC=2\pi rC=2πr

• If you know the diameter ddd, the circumference is:

C=πdC=\pi dC=πd

Here, π\pi π (pi) is a mathematical constant approximately equal to 3.14159 (often approximated as 3.14).

Steps to find the circumference:

1. Determine the radius or diameter of the circle.
2. Use the appropriate formula:
   • Multiply the radius by 2 and then multiply by π\pi π if using the radius.
   • Multiply the diameter directly by π\pi π if using the diameter.
3. Calculate the result to get the circumference.

Example:

If the radius is 8 meters:

• Diameter d=2×8=16d=2\times 8=16d=2×8=16 meters
• Circumference C=π×16≈3.14×16=50.24C=\pi \times 16\approx 3.14\times 16=50.24C=π×16≈3.14×16=50.24 meters

So, the circumference is approximately 50.24 meters

. Alternatively, you can measure the circumference physically by wrapping a string around the circle and measuring the length of the string