To work out the circumference of a circle, you multiply the diameter by Pi (approximately 3.141).

en.wikipedia.org/wiki/Circumference

The circumference of a closed curve or circular object is the linear distance
around its edge. ... Or, equivalently, as the ratio of the circumference to twice the
radius. The above formula can be r...

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

The distance around a circle on the other hand is called the circumference (c). ...
The circumference of a circle is found using this formula: C = π ⋅ d o r C = 2 π ⋅ ...

www.mathgoodies.com/lessons/vol2/circumference.html

Circumference of a circle is presented in this interactive lesson from Math ...
Another way to write this formula is: Circumference equals Pi times diameter ...

www.wikihow.com/Calculate-the-Circumference-of-a-Circle

Write down the formula for finding the circumference of a circle using the
diameter. The formula is simply this: C = πd. In this equation, "C" represents the ...

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

Learn how to find the circumference, the distance around a circle, when given the
area.

www.reference.com/math/formula-circumference-circle-7e508134800bdd34

The formula for circumference of a circle is 2πr, where “r” is the radius of the circle
and the value of π is approximately 22/7 or 3.14. The circumference of a circle ...

www.virtualnerd.com/tutorials/?id=PreAlg_11_01_0010

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

www.mathopenref.com/circumference.html

Definition and properties of the circumference of a circle. ... R is the radius of the
circle π is Pi, approximately 3.142. See also Derivation of circumference formula
...

www.math.com/tables/geometry/perimeter.htm

(pi = pi = 3.141592...) Perimeter Formulas The perimeter of any polygon is the
sum of the lengths of all the sides. Note: "ab" means "a" multiplied by "b".