What is the circumference of a circle with a diameter of 10 units?

To find the circumference of a circle, the formula used is ( C = \pi \times d ), where ( C ) is the circumference and ( d ) is the diameter of the circle. In this case, the diameter is given as 10 units.

Using the formula, we substitute the diameter:

[ C = \pi \times 10 ]

Approximating ( \pi ) as 3.14 for calculations, we proceed as follows:

[ C \approx 3.14 \times 10 = 31.4 ]

Therefore, the circumference of the circle is approximately 31.4 units, which matches the correct answer. This method demonstrates how to derive the circumference using the diameter, reinforcing the relationship between these two measurements in a circle.