Question

Find the ratio of the circumference of a circle with radius 1.125 to the circumference of a circle with diameter 2.25. Express your answer in the form a:b where a and b are relatively prime positive integers.

Answer 1

1:1

Explanation:

Answer 2

Circumference of circle 1 : Circumference of circle 2 = 1 : 2

Explanation:

Circumference of a circle = πD, where D is the diameter.

Diameter of circle 1 = 1.125

Circumference of circle 1 = π x 1.125

Diameter of circle 1 = 2.25

Circumference of circle 1 = π x 2.25

`\texttt{Ratio of circumferences = }(\pi * 1.125)/(\pi * 2.25)\\\\\texttt{Ratio of circumferences = }(1)/(2)`

Circumference of circle 1 : Circumference of circle 2 = 1 : 2