We know that the area of a circle is [tex]A= \pi r^{2} [/tex]. The relationship between area and radius is a quadratic relationship. So we know that the ratio of the areas of the circles will be equal to the ratio of the squares of the radii of the circles.
The ratio of the squares of radii between circle 1 and 2 are [tex] \frac{10^{2} }{5^{2} } [/tex], which is equal to four. Thus, the area of circle 1 is four times larger than the area of circle two.
