Question

Circle A has a radius of 3 pi. Circle B has a radius of 12 pi. Determine the ratio of the circumferences. Write answer as a fraction

Answer 1

The ratio of Circumference of circle A to B =
`1:2`

Explanation:

Circumference of a circle =
`2\pi r`

Circumference of circle:A

`radius=3\pi`

Circumference(A):

`=2*\pi *(3\pi )\\\\=6\pi *\pi \\\\=6\pi ^2`

Circumference of circle:B

`radius=12\pi \\`

Circumference:

`=2*\pi *(12\pi )\\\\=24\pi *\pi \\\\=24\pi ^2`

Ratio of Circumference of Circle:A to Circle:B

`=(6\pi^2 )/(12\pi^2 )\\\\=(1)/(2)`

The ratio of Circumference of circle A to B =
`1:2`