Math and Arithmetic

Geometry

Harvard University

How do you find the perimeter of two concentric circles?

## Answer

###### Wiki User

###### April 29, 2010 6:05AM

## The perimeter of a circle is the same as it's circumference. To find this, you will need to know it's radius or diameter.

## For example, if the diameter of a circle is 7, you could do: pi times the diameter (which is 7), or, if you want to, you could half it and have; 2 times pi times 3.5. It doesn't matter which way you have it, you will still get the same answer if it is halved correctly.

## Related Questions

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### Is the center of a circle the point of intersection for two concentric circles?

Concentric circles are the circles with the same center
therefore they do not cross with each other as the "center is not
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### How do you find the area common to circles?

pi r squared Area of the circle = pi (radius)2 square
units.
If we are supposed to find the area between two concentric circles
then, let us see the definition first.
Concentric circles have a common center and different radii.
Area of the large circle – Area of the small circle = Area of the
region between the circles.
It is called as the annulus part Source:
www.icoachmath.com