Question

If the ratio of area of two circles be $\frac{36}{64}$ what is the ratio of their radii?

• A. $\frac{6}{8}$
• B. $\frac{8}{6}$
• C. $\frac{36}{64}$
• D. $\frac{64}{36}$

Answer 1

The correct option is A $\frac{6}{8}$

$\frac{A_1}{A_2}=\frac{36}{64}$
or $\frac{\pi r_1^2}{\pi r_2^2}=\frac{36}{64}$
$\therefore$ $\frac{r_1}{r_2}=\frac{6}{8}$