Question

The ratio of the radii of two circles is 3:2. What is the ratio of their circumferences?
(3 Marks)

Answer 1

Circumference of a circle = $2\pi r$
where r is the radius of the circle
(1 Mark)
Let $r_1$ and $r_2$ be the radii of two circles respectively.

$\frac{r_1}{r_2}=3:2$ (Given)

Now, the ratio of their circumferences
= $\frac{2\pi r_1}{2\pi r_2}=\frac{r_1}{r_2}=3:2$
(2 Marks)