Circumference of a Circle
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More Lessons for Grade 6 Math
Math Worksheets
Examples, videos, worksheets, stories and songs to help Grade 6 students learn about the Circle: Area, Circumference, Radius, Diameter.
Circumference of a Circle<br. The circumference of a circle is the distance around its outer edge. Think of it as the perimeter of a circle. It depends on the radius or diameter of the circle.
The following figures give the formula for the circumference of circle. Scroll down the page for more examples and solutions.
Geometry Worksheets
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The Circumference Formula
There are two common formulas for the circumference (C) of a circle, depending on whether you know the radius or the diameter:
-
Using the diameter (d):
C=πd
Where:
C = Circumference
π (pi) is a mathematical constant, approximately 3.14159.
d = diameter of the circle (the distance across the circle passing through its center). -
Using the radius (r):
C=2πr
Where:
C = Circumference
π (pi) ≈3.14159
r = radius of the circle (the distance from the center of the circle to any point on its edge).
How to Remember the Formula
A popular mnemonic to distinguish the circumference formula from the area formula is:
“Cherry Pies Delicious!"
Cherry (for Circumference)
Pies (for π)
Delicious (for diameter)
This gives you: C=πd
You can also combine it with the area mnemonic:
“Cherry pies delicious! Apple pies are too!"
Cherry Pies Delicious, C=πd (Circumference)
Apple Pies Are Two, A=πr2 (Area)
Videos
How to find circumference of a circle given the radius or diameter?
How to calculate the circumference of a circle?
The circumference of a circle is the distance around the circle, and the formula for the circumference of a circle is 2 times pi times the radius of the circle. Find the circumference of a circle given the diameter.
This video gives several examples of the process used to find the circumference of a circle.
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