what is circumference

The circumference is the perimeter of a circle or ellipse, which is the arc length of the circle if it were opened up and straightened out to a line segment. It is also known as the "perimeter" of a circle. The circumference is the distance around a circle or any curved geometrical shape, and it is the one-dimensional linear measurement of the boundary. The circumference of a circle is the total length of the boundary of the circle. It is usually measured in units of lengths such as feet, inches, centimeters, meters, miles, or kilometers. If we cut open a circle and make a straight line, the length of the line would give us the circles circumference. The formula for the circumference of a circle is C = 2πr, where C is the circumference, and r is the radius of the circle.