Circumference of a circle with a radius of 3.
Understand the Problem
The question is asking for the calculation of the circumference of a circle given its radius. The formula for the circumference (C) is C = 2Ï€r, where r is the radius.
Answer
$C = 10 \pi$ or approximately $31.4$ if $r = 5$.
Answer for screen readers
The circumference of the circle is $C = 10 \pi$, or approximately $31.4$ if $r = 5$.
Steps to Solve

Identify the radius First, ensure you know the radius of the circle. Let's assume the radius is given as $r$.

Apply the circumference formula Next, use the formula for the circumference of a circle, which is: $$ C = 2 \pi r $$

Substitute the radius into the formula If the radius $r$ is provided, substitute it into the formula to calculate the circumference. For example, if the radius is 5, then: $$ C = 2 \pi (5) $$

Calculate the circumference Finally, perform the calculation. If $r = 5$, the calculation would be: $$ C = 10 \pi $$
If you want a numerical approximation, use $\pi \approx 3.14$ to get: $$ C \approx 10 \times 3.14 = 31.4 $$
The circumference of the circle is $C = 10 \pi$, or approximately $31.4$ if $r = 5$.
More Information
The circumference of a circle is a fundamental concept in geometry. It's essential in various realworld applications, including determining distances around circular objects.
Tips
 Forgetting to multiply by $2\pi$: Always remember to apply the full formula $C = 2\pi r$.
 Confusing radius with diameter: Ensure you use the correct measurement; the radius is half the diameter.