Question

The areas of two circles are in the radio 49 : 64. Then the ratio of their circumference is 7:16

• A. True
• B. False

Answer 1

The correct option is B False

False
Area of $1^{st}$ circle $=\pi r_1^2$
Area of $2^{nd}$ circle $=\pi r_2^2$
According to question,
$\frac{\pi r_1^2}{\pi r_2^2}=\frac{49}{64}$
$\Rightarrow \frac{r_1^2}{r_2^2}=\frac{49}{64}$
$\Rightarrow \frac{r_1}{r_2}=\frac{7}{8}$
Circumference of the $1^{st}$ circle $=2\pi r_1$
Circumference of the $2^{nd}$ circle $=2\pi r_2$
$\frac{2\pi r_1}{2\pi r_2}$
$\Rightarrow \frac{r_1}{r_2}=\frac{7}{8}=7:8$