It's goofy to subtract perimeter and area; they're in different units. We persist.
The area is [tex]s^2[/tex] and the perimeter is [tex]4s[/tex]. so the difference is
[tex]s^2 - 4s = (3 \sqrt{2})^2 - 4(3\sqrt{2}) = 18 - 12 \sqrt{2}[/tex]
Answer: choice A
