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Pi x the diameter of the circle will hive you the circumference. The diameter is double the radius so the answer to your question is pi2r.

Q: How Do you find the circumfrence when you know the radius?

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two times the radius times pi

The circumfrence is like a perimeter. It is the area around a circle. You can find the circumfrence of a circle by using this formula. Pi x R2 or Pi times the radius squared.

radius=13 area=40.82 circumfrence=8.28025477707

18.84

If you mean of a circle then they are as follows:- Circumference = 2*pi*radius or diameter*pi Area = pi*radius squared

Related questions

radius = circumference/(2*pi)

If you do not have the area, what do you have? The radius is half the diamiter The radius is PieR2 Worked backwards if you know the circumfrence.

the circumfrence of a circle is pi times it's radius squared.

two times the radius times pi

The circumfrence is like a perimeter. It is the area around a circle. You can find the circumfrence of a circle by using this formula. Pi x R2 or Pi times the radius squared.

The circumference (c) of a circle = 2πr (where r = radius). Therefore if you know the circumference, the radius (r) = c/2π.

radius=13 area=40.82 circumfrence=8.28025477707

Divide the area by pi then square root your answer which will give the radius of the circle and use 2*pi*radius to find the circumference.

18.84

If you mean of a circle then they are as follows:- Circumference = 2*pi*radius or diameter*pi Area = pi*radius squared

The circumference (not circumfrence!) is given by the equation C = 2*pi*r where r is the radius. So r = C/(2*pi) where pi is the irrational number that is approx 3.14159 or even more approximately, 3.14.

22*pi