If the radius of the circle is 4, what is the circumference?

If the radius of the circle is 4, what is the circumference?

• A. 12.56
• B. 25.12
• C. 16.00
• D. 8.00

Answer: (B)

To find the circumference of a circle, the formula used is \(C = 2\pi r\), where \(C\) represents the circumference and \(r\) is the radius of the circle. In this case, the radius is given as 4. When you plug this value into the formula, it becomes: \[ C = 2\pi(4) \] \[ C = 8\pi \] Next, using the approximate value of \(\pi\) as 3.14, we calculate: \[ C \approx 8 \times 3.14 = 25.12 \] Thus, the circumference of the circle is approximately 25.12, which corresponds to the correct choice. This calculation demonstrates how the relationship between the radius and the circumference is solidified through the multiplication by \(2\pi\), emphasizing the importance of understanding circle properties.

To find the circumference of a circle, the formula used is (C = 2\pi r), where (C) represents the circumference and (r) is the radius of the circle.

In this case, the radius is given as 4. When you plug this value into the formula, it becomes:

[

C = 2\pi(4)

]

[

C = 8\pi

]

Next, using the approximate value of (\pi) as 3.14, we calculate:

[

C \approx 8 \times 3.14 = 25.12

]

Thus, the circumference of the circle is approximately 25.12, which corresponds to the correct choice.

This calculation demonstrates how the relationship between the radius and the circumference is solidified through the multiplication by (2\pi), emphasizing the importance of understanding circle properties.