Question

The area of a circle was 49 times the area of a circle with radius 3.find the Radius of the bigger circle.

Answer 1

let's assume that the radius of the bigger circle is R.
Are of a circle is given by
Ar = πr²

Now, it is given that
πR² = 49(π(3²))
So R= √(49x9)
= 7x3
= 21 sq unit

Answer 2

Let the radius of bigger circle=r
radiustof smaller circle =3
According to question :
πr²=49π(3)²
r²=49×9
r=7×3
r=21