To find the circumference of a circle when the diameter is known, you can use the formula:

$C = \pi \times d$

where:

• $C$ is the circumference,
• $\pi$ is approximately 3.14159,
• $d$ is the diameter.

Given:

• $d = 156$ units,

Now, calculate the circumference:

$C = \pi \times 156 \approx 3.14159 \times 156 \approx 490.09 \text{ units}$

So, the circumference of the circle is approximately 490.09 units.

Would you like more details or have any questions about this problem?

Here are 5 related questions for further practice:

1. What is the circumference of a circle with a diameter of 200 units?
2. If the radius of a circle is 78 units, what is the circumference?
3. How do you calculate the area of a circle if the diameter is given?
4. If a circle has a circumference of 314.16 units, what is its diameter?
5. What is the difference in circumference between two circles with diameters of 156 units and 100 units?

Tip: Remember that the circumference of a circle is directly proportional to its diameter; doubling the diameter doubles the circumference.