en.wikipedia.org/wiki/Circumference

The circumference of a closed curve or circular object is the linear distance
around its edge. The **circumference of a** ...

www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/a/radius-diameter-circumference

Learn the relationship between the radius, diameter, and **circumference of a**
**circle**.

www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/e/find-the-radius-or-diameter-of-a-circle-from-the-circumference-or-area

Find the **circumference of a circle** when given either the radius or diameter. Find
the radius or diameter of a circle when given the circumference.

www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-circumference-circle/v/circumference-from-area

The usual definition of pi is the ratio of the **circumference of a circle** to its diameter
, so that the **circumference of a circle** is pi times the diameter, or 2 pi times the ...

www.mathplanet.com/education/pre-algebra/more-about-equation-and-inequalities/calculating-the-circumference-of-a-circle

The distance around a rectangle or a square is as you might remember called the
**perimeter**. The distance around a **circle** on the other hand is called the ...

www.mathgoodies.com/lessons/vol2/circumference

A **circle** is a shape with all points the same distance from the center. It is named
by the center. The **circle** to the left is called **circle** A since the center is at point A.

virtualnerd.com/pre-algebra/perimeter-area-volume/circles/circumference/circle-circumference-from-diameter

Then you can use the formula for the **circumference of a circle** to get the answer!
... circle; find circumference; diameter; pi; multiply; pi times diameter; solve for ...

www.aaamath.com/geo612x4.htm

An interactive math lesson to calculate the **circumference of a circle**.