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

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'.

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