Math Dictionary / Circumference

Circumference

Circumference is the distance around a circle.

GeometryGrade 6Grade 7Grade 8Algebra 1GEDSATACT

What it means

It is the circle version of perimeter and is found with formulas such as C = pi d or C = 2pi r.

Also called: circle perimeter

Examples

If diameter = 10, circumference is about 31.4
C = pi d
C = 2pi r

Common mistake

Circumference is a distance around the circle, not the area inside it.

Try one

Question: Which formula uses diameter to find circumference?

Show answer

C = pi d.

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