Circumference of a circle is equal to the perimeter of a square. What is the ratio of area of circle to the area of square? 

Correct option is A

Given:
Circumference of a circle = Perimeter of a square
Formula Used:
Circumference of a circle = 2πr
Perimeter of a square = 4a
Area of circle = πr²
Area of square = a²
Solution:
From the given,
2πr = 4a
=> πr = 2a
=>$$\frac ra$$​ = $$\frac{2}{\pi}$$​
Required ratio = $$\frac{\pi r^2}{a^2} = \pi \left( \frac{r^2}{a^2} \right) = \pi \times \frac{4}{\pi^2} = \frac{4}{\pi} = \frac{4}{\frac{22}{7}} = \frac{4 \times 7}{22} = \frac{28}{22} = \frac{14}{11}$$​​