Circumference of a circle

L=2\pi r

Result unit: length units

What it describes

The length of a circle of radius

r

L

circumference (length of the circle)

r

radius

The circumference is directly proportional to the radius. The constant

\pi

is the ratio of the circumference to the diameter.

Circumferences of circles, arc lengths, circular motion.

The radius is

r=5

. Find the circumference of the circle.

Substitution

r=5

Result

L=2\pi\cdot5=10\pi\approx31.4

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