Answer:
62.8 in2
Explanation:
With round pizza we need to 
find the area of each pizza in 
square inches, then determine 
the difference. 
The area of a circle is given by: 
A = πr2 
 
12 inch diameter, radius = 6 
a = π(62) = 36π in2 
 
8 inch diameter, radius = 4 
a = π(42) = 16π in2 
 
Difference: 36π - 16π = 20π in2 
 
using 3.14 for pi, the difference is 
20(3.14) = 62.8 in2