Concise Selina Solutions for Class 9 maths Chapter 15 Construction of Polygons

As a general definition, a polygon is defined as any geometric figure bound by three or more sides; and a regular polygon is a polygon with equal sides and equal base/external base angles [1-3]. Other usual methods of construction that involve angle constructions and transfer of angles. The simplest regular polygon is the equilateral triangle, which consists of three edges of equal length and three angles between each pair of edges to be 60 degrees. Three edges are the smallest number of edges to construct a polygon because two edges form an angle, and one edge is a segment. In geometry, a simple polygon is a polygon that does not intersect itself and has no holes. That is, it is a flat shape consisting of straight, non-intersecting line segments or "sides" that are joined pairwise to form a single closed path. If the sides intersect then the polygon is not simple.

There are two main types of polygon - regular and irregular. A regular polygon has equal length sides with equal angles between each side. Any other polygon is an irregular polygon, which by definition has unequal length sides and unequal angles between sides.

A plane shape (two-dimensional) with straight sides. Examples: triangles, rectangles and pentagons.