The area of a pentagon is found through the following formula:
[tex]A = \frac{1}{4} \sqrt{5(5+2 \sqrt{5}) } * s^{2} [/tex]
s is equal to the side length.
Plug 12 and 28 into the formula.
A(12) = 247.75
A(28) = 1348.85
Divide the first result by the second result.
[tex] \frac{247.75}{1348.85} [/tex] ≈ [tex]0.1836[/tex]
9/49 is equal to this decimal.
The answer is 9/49.