I plugged it in to a truncated square pyramid calculator and got v=76
the formula for this shape is V=1/3(A squared+AB+B squared)H.
Answer: Square, 24 square inches
Step-by-step explanation:
Given
Diameter of round pizza 
Side of square pizza 
Area of circle 
The area of a square is 

The area of square pizza is

Clearly, the area of square pizza is more and the difference in their area is

Step-by-step explanation:
my answer is in the image above