Things You'll Need:
- Formula for find the circumference of a circle.
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Step 1
To begin solving this problem you will need to use the formula for finding the circumference of a circle which is: C=2πr. 'C' stands for circumference (the perimeter of a circle), that little symbol that looks like an odd 'n' stands for pi (equals 3.14 and is the ratio between a circles diameter; the distance from one side of the circle to the other side, and circumference) and the 'r' stands for radius (half of the diameter).
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Step 2
Now that you know the formula all you have to do is plug in the givens (the information that the problem gives you such as the radius or diameter). Let's say the problem says that the diameter is 12. You might think that that doesn't make any sense because you can't plug the diameter into formula, and you're right. HOWEVER, you can plug in the radius (which, remember, equals half of the diameter). So in this case the radius would equal 6 which is half of 12 (diameter!). Not only that, but sometimes you can even use the formula C=πd to find the circumference, depending on your givens.
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Step 3
Now you can plug your given into the problem: C=2π6. What this means is to multiply the radius (6) by pi (3.14) and 2; C=2(3.14)(6). After your multiplication you should get C=37.68. You may be asked to round the number off to a whole number which would then be 38!
Comments
anthony2 said
on 7/20/2009 I always had a hard time with this thanks!
Walkaboutangel said
on 4/14/2009 It is great to see someone who knows simple geometry... it can be so useful in life... the circumference of a circle is useful information for example when considering place settings on round tables.....
lkrause2 said
on 3/6/2009 It's great to see someone posting articles on math - the circumference of a circle could be useful for anyone who is designing anything that has a circle in it - for example, sewing or woodworking. Thanks 5*