The circumference is the distance around the edge of a circle. It can be calculated using the formula C = 2\pi r , where C represents the circumference, \pi (approximately 3.14) is a constant, and r is the radius of the circle. The radius is the distance from the center of the circle to any point on its edge. Circumference is important in various fields, including geometry and engineering. It helps in determining the size of circular objects, such as wheels or pipes, and is essential for tasks like measuring land or designing circular structures. Understanding circumference is fundamental in mathematics and practical applications.