The book was likely finished sometime in late 1987 or early 1988]. II.The collapse of Communism in the Balkans. It is likely that Gorbachevâs ideas for liberalizing East European communist states worked out best in the Balkan states of Bulgaria and Romania.
A polygon is a  closed plane figure made of three or more straight line segments. The term originated from ancient Greek polygonon, which breaks down to polus (many) and gonia (angle). A polygon is a closed plane figure made of three or more straight line segments.
Definition of a Polygon. A polygon is any 2-dimensional shape formed with straight lines. Triangles, quadrilaterals, pentagons, and hexagons are all examples of polygons. The name tells you how many sides the shape has. For example, a triangle has three sides, and a quadrilateral has four sides. So, any shape that can be drawn by connecting three straight lines is called a triangle, and any shape that can be drawn by connecting four straight lines is called a quadrilateral. All of these shapes are polygons.