Convex polygons

A broken line is called closed if its ends are connected by a segment.
If all links of a simple closed polyline do not lie on one straight line, then this is a polygon . Then the points of the broken line are called the vertices of the polygon , and the links are called the sides of the polygon .
A polygon with n vertices is called an n-gon .



A polygon is called convex if it lies in one half-plane with respect to any straight line containing its side. A1A2A3A4A5A6A7 is a convex polygon.



B1B2B3B4B5 is a nonconvex polygon.