How to find the area of a circle just given the circumference? The circumference is 64pi

Question

jim_thompson5910 · Answer

Circumference = 2*pi*radius

C = 2*pi*r

64pi = 2*pi*r

solve for r to get the radius

jim_thompson5910 · Answer

once you have the radius, you can use it to find the area using the formula

A = pi*r^2

anonymous · Answer

How do I find the radius?

jim_thompson5910 · Answer

what do you get when you solve 64pi = 2*pi*r for r?

anonymous · Answer

64/3.14=20.382/2=10.1910

jim_thompson5910 · Answer

64pi = 2*pi*r

2*pi*r = 64pi

r = 64pi/(2*pi)

r = 64/2

r = 32

anonymous · Answer

I thought it was divided by pi? Ok let me plug that into the other equatin you gave me

jim_thompson5910 · Answer

64pi divided by 2pi = 32

because the two "pi" terms cancel and you're left with 64/2 = 32

anonymous · Answer

I keep getting 200.96 but thats not right

jim_thompson5910 · Answer

A = pi*r^2

A = 3.14*32^2

A = 3215.36

anonymous · Answer

Thats not one of the answers given.

jim_thompson5910 · Answer

what are your answer choices?

anonymous · Answer

I got 1023.

anonymous · Answer

I did 
A = 3.14 x (r x r)
 A = 3.14 x 326.045
 A = 1023

jim_thompson5910 · Answer

how did you get 326.045 ?

jim_thompson5910 · Answer

btw, what are your answer choices?

anonymous · Answer

1. 128pi in^2
2. 256 pi in^2
3. 1024 pi in^2
4. 16 pi in^2

jim_thompson5910 · Answer

oh you just leave the pi alone

jim_thompson5910 · Answer

A = pi*r^2

A = pi*(32)^2

A = pi*(1024)

A = 1024pi

anonymous · Answer

Thanks

jim_thompson5910 · Answer

np