Question

The radius of the circle when the circumference is 48 pi

Answer 1

Below

Explanation:

circumference = pi * d but d = 2r so

Circumference = pi * 2 r

48 pi = pi * 2 r divide pi out from both sides

48 = 2r divide both sides by 2

24 units = r

Answer 2

Answer: 1357.16802635

Explanation:

So we are told that 48π = Circumference

We know that 2πr is also equal to the circumference.

Therefore we can see that the diameter (half the circumference) is equal to 48. Since the radius is half the size of the diameter, we will have to divide the diameter (48) by 2.

48/2 = 24

Our radius is 24.

We are told to multiply the radius by 9.

24 x 9 = 216

New radius = 216

Now we need to solve for the circumference again with our new radius.

C = 2πr

Plug in 216 for the radius

C = 2π(216)

Multiply the radius by 2 according to the circumference formula

C = 432π

Multiply our diameter of 432 by pi

C = 1357.16802635

We can round if we need to

C ≈ 1357 cm