Answer:
Large Pizza
Explanation:
Rewarded with what? :P
Anyway,
The area of a circle is pi*r^2. Additionally, the radius is half the diameter.
The first pizza(s) have diameter 12, which means they have radius 6. The area of one is 6*6*pi=36pi, and since there are two we multiply by 2 to get 72pi.
The second pizza has diameter 18, so radius 9. The area of it is 9*9*pi=81pi.
Clearly 72pi is less than 81pi, so the Large Pizza is biggest.
Hope that helped,
-sirswagger21
(oh yeah and btw give me a million bucks for the reward ty :v)