Question

if radius of the big circle is double of a small circle,then the area of the big circle is____________ of the small circle​

Answer 1

4 Times

The area of a circle is equal to the square of its radius times pi. The circumference of a circle is equal to the diameter times pi.So when you double the radius, the area goes up by 4 times because 2 squared is 4. The area will always go up by the square of how much the radius goes up.

Answer 2

Given,

Radius of big circle is double of a small circle.

To find,

Number of times by which the area of big circle is greater than the area of small circle.

Solution,

We can simply solve this mathematical problem by using the following mathematical process.

Now,

Let, the radius of small circle = r unit

So, radius of big circle = 2×r = 2r unit

Now,

Area of small circle = π×(r)² = πr² sq.unit

Area of big circle = π×(2r)² = 4πr² sq.unit

Let, Number of times by which the area of big circle is greater than the area of small circle = x

Thus,

x × Area of small circle = Area of big circle

x × πr² = 4πr²

x = 4πr²/πr²

x = 4

Hence, If radius of the big circle is double of a small circle,then the area of the big circle is 4 times of the small circle.