I think it would be 4.
8 breaks down to 4(2) and 12 breaks down to 4(3). Let me know if that helps!
The process for finding the product of two integers is by multiplying them .
we know that
The formula of the surface area of the cone is equal to

where
SA is the surface area
r is the radius of the cone
l is the slant height
in this problem we have

Solve the formula for l

substitute the values

therefore
<u>the answer is</u>
The slant height is 
3
Circumference is 2πr, and the large cake has a radius 3 times the radius of the small cake. So, the circumference of the large cake will be 3 times that of the small cake.