# Diameter is 7/22 cm. What is the circumference?

enginr | Certified Educator

calendarEducator since 2015

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We are given a diameter of 7/22 centimeters.

A diameter is the length of a straight line segment which passes through the center of a circle and has its endpoints on the circle itself.

The circumference of a circle is simply the length of one complete revolution of the circle.

The circumference of a circle is equal to the diameter (D) times pi (`D*pi` ). The circumference of a circle is also often stated as `2*pi*R`  where R is the radius. However, the diameter is simply twice the length of the radius, so we can see the two statements for circumference are equivalent.

`2*R=D` thus

`2*R*pi=D*pi`

So the circumference of our circle is:

`D*pi=(7/22)*pi=0.999 ` centimeters

Recall that the definition of pi is the circumference of a circle divided by its diameter.

Pi = circumference / diameter = approximately 3.14

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## Related Questions

misssilvestri | Student

We know that the formula for circumference of a circle is `C=2pir or`

`C=D*pi`

• The diameter of a circle is the distance from one point on the circle, to another point on the circle passing through the center of the circle.
• The radius is the distance between any point on the circle to the center of the circle.
• From this information we can conclude that the radius is half the distance of the diameter.

If you are given that the diameter is 7/22, then half of that would be 7/44.