In the image you provided, the question is asking for the circumference of a circle, given that the diameter is 4 cm. The formula for the circumference of a circle is:

$C = \pi \times d$

Where:

• $C$ is the circumference,
• $d$ is the diameter, and
• $\pi$ (pi) is approximately 3.14.

So, using the given diameter of 4 cm:

$C = 3.14 \times 4 = 12.56 \, \text{cm}$

Thus, the circumference of the circle is approximately 12.56 cm.

Would you like more details or have any further questions about this? Here are some related questions:

1. How do you calculate the area of a circle if given the radius?
2. What is the relationship between the radius and diameter of a circle?
3. How does the circumference formula change when using a different approximation for pi?
4. What is the significance of pi in other geometric formulas?
5. How would you calculate the circumference if the radius is provided instead of the diameter?

Tip: Always ensure to use a value of pi that is appropriate for your level of precision (for everyday calculations, 3.14 is often enough, but for higher precision, using a more exact value may be needed).