Question

One circle has a circumference of 123 cm. Another circle has a circumference of 32 cm. What is the ratio of the radius of the

smaller circle to the radius of the larger circle?
3:8
8:3
1:3
3:1

Answer 1

Answer: 1:3

Explanation:

Cir. of the bigger circle = 123 cm

r = C / 2π

r = 123 / 2π = 19.58

Cir of smaller circle = 32 cm

r = 32 / 2π = 5.09

Ratio = 5.09 : 19.58

= 1:3

Answer 2

1:3

Explanation:

First find the measure of radius for both circles:

Circle 1:

2 x pi x r = 123

r = 123 divided by 6.28 = 19.58

Circle 2:

2 x pi x r = 32

r = 32 divided by 6.28 = 5.09

So, Ratio:

5.09 : 19.58

Approximately 1:3 ( 6:18)