Answer:
The radius of the pizza would be 8 inches.
Explanation:
The diameter is the line that goes through the circle, essentially cutting it in half. While the radius is always going to be half of that line.
Therefore if the diameter is 16, the radius will be half of that, which is 8.
(Here's a picture to help you understand the concept better⤴⤴⤴)
Hope this helps you :)