Find the circumference of a circle using the formula 2 x π x r. You need the value of π, or pi, and the radius of the circle. More »

To measure the circumference of a circle, first measure the diameter and multiply that number by the mathematical constant pi. The diameter is a straight line that goes from one side of the circle to the other and passes... More »

The perimeter of a semicircle is 1/2 of the circumference of the corresponding complete circle plus the diameter of the circle. The distance around the outside of a semicircle is generally called its perimeter. More »

The circumference of a circle is the distance around the outskirts of the circle. Knowing the radius of any circle allows one to calculate its circumference. More »

If the circumference or the area of a circle is known, pi can be used to find the diameter and the radius of that circle. Likewise, if the radius or diameter is known, pi can be used to find out the circumference or the ... More »

To calculate a circle's diameter from its circumference, one should divide the circumference by the constant pi, which is an irrational number approximately equal to 3.14159265358979. More »

To find the perimeter of a circle, also known as the circumference, plug the dimensions of the circle into the formula ((pi)(d). This formula stands for pi (approximately 22/7) times the diameter of the circle (d). More »