Question

Find the radius of a circle with the given circumfrence.

15pi ft.

A. 30 pi ft.
B. 30 ft.
C. 7.5 pi ft.
D. 7.5 ft.

Answer 1

first of al do you know how to find the radius...what is the formula?

Answer 2

They don't tell me. However, the formula to find the circumfrence is:

C=2*pi*radius

Answer 3

when it says 15 pi feet does it mean pie as in 3.14?

Answer 4

Yes..

Answer 5

i got this guys
ok then you will do the formula in reverse...solve for R not c...so first find out what 15*3.1428 is and that is "C" then work out the problem... like this
({15*3.1428}/3.1428)/2=r...

Answer 6

tell me your answer...dont just do it and leave...

Answer 7

Hold up you wrote out pi completely .... They only want me to solve with pi as 3.14 not 3.1428

Answer 8

...lol i promise...its not written out completely...lol...but it is to the fourth number...just solve it that way...it gives a clearer answer

Answer 9

I got 7.49

Answer 10

circumference = pi * diameter =pi * 2* radius

you have the circumference. you have pi, and you have 2. just solve for the radius.

Answer 11

Okay so basically it's this


15pi=2*pi*r

Answer 12

they didn't times it by pi. the circumference either 15pi or 47 ft.
its just in a different form. this means in its pi form, you only need to divide it by 2.
Which gives you the radius of 7.5 ft.

Answer 13

does this make sense?

Answer 14

Yea it does

Answer 15

Remember that the circle circumference is 2 * radius * Pi. So, given 15 * Pi, that equates to the circle circumference being 2 * Pi * 7.5. Now, given this information provided to you, can you determine what the answer would be? If you have not figured it out, 7.5 * Pi best matches the third choice from the information provided here.

Answer 16

whoops dean is correct.

Answer 17

thank you for clearing that up

Answer 18

Haha it's alright. Thanks Dean (: I would give you best response but I'm on an iPhone right now and it won't let me. Soo I'll give you best response when I get on my computer (: