What makes a polygon complex/simple?
Hmmm....
What is the degree of a polygon?
The degree of a polygon is the number of sides it has.
What is a self-intersecting polygon?
A polygon with (at least) two edges that have an intersection other than their
endpoints is self-intersecting.
What is a polyhedron?
A polyhedron is a solid that is bounded by a set of polygons whose
edges are each a member of an even number of polygons (and that satisfies
some additional constraints).