Circumference is the distance around a circle, found by multiplying the diameter by pi, or the radius by 2 pi. It is the circle equivalent of perimeter.
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.