2. When n > 3, the number of edges becomes n- 1 if it is cut along the continuous line of other two points adjacent to a certain point.

When n=3, if it is cut along the connecting line of any point on another side adjacent to one point, the number of sides becomes 3.

If n≥3 is cut off from a point on the connecting line between two other points adjacent to a point, the number of edges becomes n+ 1.