Question 2
A convex polygon is divided into some triangles. Let $V$ and $E$ be respectively the set of vertices and the set of edges of all triangles (each vertex in $V$ may be some vertex of the polygon or some point inside the polygon). The polygon is said to be good if the following conditions hold:
i. There are no 3 vertices in $V$ which are collinear;
ii. Each vertex in $V$ belongs to an even number of edges in $E$.
Find all good polygon.
i. There are no 3 vertices in $V$ which are collinear;
ii. Each vertex in $V$ belongs to an even number of edges in $E$.
Find all good polygon.