Circumference measurements refer to the distance around a circular object. This measurement is crucial in various fields, including geometry, engineering, and everyday activities like measuring the size of a round table or a tire. The formula to calculate the circumference is C = 2πr, where C is the circumference and r is the radius of the circle. To find the circumference using the diameter, the formula is C = πd, where d is the diameter. Understanding circumference is essential for tasks such as designing circular objects, calculating areas, and ensuring proper fit in mechanical applications.