Explanation
The area of a circle \(=\pi r^{2}\). Letting the radius of the smaller circle = r, the radius of the larger circle = 2r, and its area \(=\pi(2 r) 2\), or \(4 \pi r^{2}\). The ratio of the smaller circle’s area to the larger circle’s area is \(\pi r^{2} \div 4 \pi r^{2}\) , or 1:4.