Explanation:
If I have a square with sides of 2m, it has an area of 4m^2.
If I have a square with sides of 3m, it has an area of 9m^2.
You might divide 4 by 9 to get the ratio of areas.
A more "mathematical" approach is look at the equation for the area of a square...
[tex]A = a^2[/tex] where a is the length of the side of the square.
I could setup a ratio of the area of two squares as...
[tex]\frac{A_2}{A_3} = \frac{a_2^2}{a_3^2}[/tex]
