Question

The ratio between the areas of two circles is $16:9$. Find the ratio between their radii:

• A. $3:4$
• B. $16:9$
• C. $4:3$
• D. None of these

Answer 1

Answer: (C)

$4:3$

Area of cicle $=\pi r^2$.

Given ratio of areas of two circles is $16:9$.

Hence,

$\frac{\pi r_1^2}{\pi r_2^2}=\frac{16}{9}$

$⟹\frac{r_1}{r_2}=\sqrt{\frac{16}{9}}=\frac{4}{3}$

Hence ratio of their radii is $4:3$.