First, draw a diagram of the pizza showing the three axes of symmetry:
Notice that the pizza is being cut in 6 equal parts. Then, the area of each slice, which is the same as the area of each paper base, is 1/6 of the total area of the pizza.
Since the diameter of the pizza is 50cm, then its radius is 25cm. The area of a circle with radius r is:

Replace r=25 to find the area in square centimeters. Next, divide by 6 to find the area of each paper base:

Then, the area of each paper base is:

Therefore, the area of each paper base is approximately 327 square centimeters.