Introduction: Circumference of a Circle

Picture of Circumference of a Circle

How to find the Circumfrence of a Circle, the Quick and Easy Way!

Everybody here learned how to do this in 8th grade math, then again in geometry, but who actually remembers? Well, here's a brush up, in case you ever need to know this.

Let the Mathematics begin!!

Step 1: Materials

Picture of Materials

There are a few general requirements to do this. You need:
A. A Circle or Circular object (coins, hockey puck, etc.)
B. A Ruler, cm. or in. depending on which you use.
C. A Brain, I'm afraid so...
D. A Calculator, or if you're a whiz, C.

Step 2: Step A.

Picture of Step A.

You need to locate two points, let's call them point A and point B, on opposite ends of the perimeter of the circle, as far away as they can be and still be on the edge. So that if a line went through them, it would go through the middle of the circle.

Step 3: Step B.

Picture of Step B.

Now, measure the distance between the two points, this should be fairly easy to do. Try to get it as exact as possible.

The picture below shows what you should have (kind of), you're measuring the diameter.

Step 4: Mathematics

Picture of Mathematics

Now comes the Hard part. You take the measurement you just took, eg. 2 in., and multiply it by Pi (3.14), then you get the circumference of the circle, eg. 6.28, If you need help multiplying, Kiteman shows you how at Have fun! And don't poke your eye out on the circle!!


Chromatica (author)2010-03-03

 I believe you can also use Pi x Pi to find the circumference when you have the radius.

Wasagi (author)Chromatica2010-03-03

 Or you could multiply the radius by 2 then by pi. Haha, we're on circles now, but we have done nothing with this kind of stuff...

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