What is the distance around a circle called?

The distance around a circle is known as the circumference. This term specifically refers to the linear measurement that encompasses the circle's entire boundary. The formula for calculating the circumference of a circle is ( C = 2\pi r ) or ( C = \pi d ), where ( r ) represents the radius and ( d ) represents the diameter. The circumference is a critical concept in understanding circular shapes and their properties.

In contrast, the area refers to the space contained within the circle, not its perimeter. The diameter is a straight line segment that runs across the circle, passing through the center and connecting two points on the circumference; it measures the length across the widest part of the circle but does not provide the distance around it. The radius is half of the diameter and measures the distance from the center of the circle to any point on the circumference, also not indicating the total distance around the circle.