To find the circumference of a circle, we use the formula:

$C = 2\pi r$

Where:

• $C$ is the circumference
• $r$ is the radius
• $\pi$ is approximately 3.1416

Given that the radius $r = 10.4$ ft, we can substitute this value into the formula:

$C = 2 \times 3.1416 \times 10.4$

$C \approx 65.3 \, \text{ft}$

So, the circumference of the circle is approximately 65.3 feet.

Would you like more details on this formula or how to apply it in different situations?

Here are 5 related questions you might find interesting:

1. How does changing the radius affect the circumference of a circle?
2. What would be the area of this circle with a radius of 10.4 ft?
3. How do you calculate the area if you are only given the circumference?
4. How do you estimate π to different levels of precision (e.g., using 3.14, 22/7, etc.)?
5. What would happen to the circumference if the radius was doubled?

Tip: When calculating circumference or area, always be sure to keep track of the units used (in this case, feet) to ensure your final answer is in the correct measurement.