The solution is very clever. However, it is incomplete. In addition to the equally divided markings around the circumference, you also need to know the midpoint of the circle. Without the midpoint, the cuts may still yield unequal slices. Fortunately, using the author's same technique, you can easily produce the midpoint by making marks at the opposite ends of a single loop. Those two additional markings provide a guide for you to make cuts into the midpoint of the pizza.