Texas Class C Wastewater Treatment License Practice Exam

The formula to calculate circumference of a circle is given by the equation that involves the diameter and the constant π (Pi). Specifically, the circumference is calculated as π multiplied by the diameter. This relationship holds true because π represents the constant ratio of the circumference of any circle to its diameter.

Using this formula demonstrates how the distance around the circle (circumference) scales in proportion to its size (diameter). While there are variations that involve the radius (which is half of the diameter), the most straightforward and directly relevant formula in this case is indeed π multiplied by the diameter. This makes it clear why this option is the correct choice for calculating circumference.