Question

What is the area of a circle whose circumference is 1447 meters? (Use π = 3.14)

Answer 1

Do you know the formulas for area and circumference?

Answer 2

No.

Answer 3

A = πr² and C = 2πr

Answer 4

Oh okay.

Answer 5

I have to find half of 1447, so I can plug it into the "r"

Answer 6

You can use the circumference formula to find r. Then use the r to get area.

Answer 7

So not just half of 1447. You also have to divide by 3.14

Answer 8

Yes. Okay.

Answer 9

Since it's \(2πr\), wouldn't it be \(2 \times\ 3.14 \times\ r = 1447\) ??

Answer 10

yes that's right

Answer 11

So now it's \(6.28 \times\ r\) ??

Answer 12

yes

Answer 13

That's what I got

Answer 14

\(~r=\frac{ 1447 }{ 6.28 } = 230.41\)

Answer 15

I meant that..

Answer 16

So now I have the radius.

Answer 17

So now use that to find A

Answer 18

Okay.

Answer 19

\(A=3.14 \times\ 230.41 \times\ 230.41\)

Answer 20

yep

Answer 21

Did you multiply it out yet?

Answer 22

I got \(166698.73\). I'm not sure if that's right.

Answer 23

Yes I think that's a good answer. I didn't round and I got 166,704.54. I think it's an acceptable amount of error for such a large number.

Answer 24

Okay. Thank you so much.

Answer 25

you're welcome

Answer 26

Heck I got 166,704.54 also
wow this openstudy has bounced me out 2 times already.

Answer 27

It's okay. Thank you, as well. c: