What formula is used to calculate the circumference of a circle?

The circumference of a circle is calculated using the formula C = 2πR, where C represents the circumference, R is the radius of the circle, and π (pi) is a mathematical constant approximately equal to 3.14159.

Option A, which states "pi x Diameter," can be related back to the formula for circumference because the diameter (D) of a circle is twice the radius (D = 2R). Therefore, when you multiply the diameter by pi (C = πD), you ultimately arrive at the circumference as well.

This approach aligns with the understanding that the diameter is a critical aspect of calculating circumference, reinforcing the concept that both the radius and diameter are interconnected in circle geometry. The focus on diameter highlights its role in establishing measurements and understanding the properties associated with circular shapes, which is fundamental in the study of geometry and power engineering applications.

Other options, while valid in their own contexts, do not directly answer the question of circumference calculation.