The image shows a circle with a line representing the radius of the circle, labeled with a length of 4 units.

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

$C = 2\pi r$

Where:

• $C$ is the circumference,
• $\pi$ is approximately 3.14159,
• $r$ is the radius of the circle.

Here, the radius $r = 4$.

Substituting this into the formula:

$C = 2 \times 3.14159 \times 4 = 25.13272$

Rounding to the nearest hundredth, the circumference is:

$C \approx 25.13$

Final Answer:

The circumference of the circle is approximately 25.13 units.

Would you like a detailed explanation of the steps, or do you have any further questions?

Here are 5 related questions to explore:

1. What is the formula for the area of a circle, and how would you compute it with the same radius?
2. How would the circumference change if the radius was doubled?
3. Can you find the diameter of the circle given the radius?
4. How would you calculate the arc length of a quarter of this circle?
5. What is the relationship between the diameter and the circumference?

Tip: The diameter of a circle is always twice the radius, and the circumference can also be calculated as $C = \pi d$, where $d$ is the diameter.