This is area of a circle.
A = π[tex] r^{2} [/tex]
FM = π[tex] 40^{2} [/tex]
AM = π[tex] 4^{2} [/tex]
Since π will cancel itself out for both, you only need to compare the square of 40 to 4.
[tex] 40^{2} [/tex] = 1600
[tex] 4^{2} [/tex] = 16
Thus, 1600 is 100 times greater than 16.
1600 * 3.14 = 5024
16 * 3.14 = 50.24
100 times more area. This is because 40 is 10 times greater than 4 and squaring it creates the 100 times.