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1 vote
If the circumference of a circle is 2 pi what is the radius

User Shaheeda
by
8.2k points

2 Answers

6 votes
c=2pir
r=radius
c=circumference

given
c=2pi
2pi=c=2pir
2pi=2pir
divide both sides by 2pi
1=r
radius is 1 unit
User Shivam Singla
by
8.6k points
7 votes
C = 2 * pi * r

Plug in what we know:

2pi = 2 * pi * r

Divide 2 pi to both sides:

r = 1

(Remember, anything divided by itself is equal to 1)

A = pi * r^2

Plug in what we know:

A = pi * 1^2

A = pi * 1

A = 1 pi

So the area is '1 pi' or just 'pi'.

User Hitesh Modha
by
7.6k points

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