Question

If the ratio of circumference of two circles is 5:7, then find the ratio of its diameters.

Answer 1

Circumference of a circle = $2\pi$r
= $\pi$d [$\because$ d=2r]
Ratio of circumference of a circle = 5:7

$\Rightarrow \frac{\text{circumference of circle 1}}{\text{circumference of circle 2}}=\frac{5}{7}$ $\left[1Mark\right]$

$\Rightarrow \frac{\pi d1}{\pi d2}=\frac{5}{7}$

$\Rightarrow \frac{d1}{d2}=\frac{5}{7}$ $\left[1Mark\right]$