Type of Polygons

Definition

A polygon is a two-dimensional shape form with more than three straight lines.

In a polygon each side must be intersect exactly two other sides, but only at their end points and have a common endpoint. The sides have must noncollinear.

The name of a polygon usually depends on how many sides or lines the shape has.

The name of building house united states department of defense is called pentagon since it has 5 sides.

Any shape that can be drawn by three connecting straight lines is a triangle, shape that can be drawn by four connecting straight lines is a quadrilateral, and shape that can be drawn by five connecting straight lines is a pentagon.

if a polygon has three sides it’s called triangle, if it has four sides it’s called quadrilateral, if it has five sides it’s called pentagon.

Note: A circle is not a polygon because it is formed with curved line, if any curved line is used to form a close figure than it will not be a polygon.

There are some names of polygons that usually occur in everyday.

                  Sides                 Polygon 

                   3                     triangle

                   4                     quadrilateral

                   5                     pentagon

                   6                     hexagon

                   7                     heptagon

                   8                     octagon

                   9                     nonagon

                  10                    decagon

                  12                    dodecagon

                  n sides              n-gon 

Regular polygon

A polygon which has all sides are congruent(equal) and all angles are congruent (equal) is known as a regular polygon.

If a triangle has all the sides are same and all the angles are same then it is a equilateral triangle or a regular triangle.

If a quadrilateral has all the sides are same and all the angles are same then it is a square or a regular quadrilateral..

Irregular polygon

A polygon which has all sides are not congruent(not equal) or different in length and all angles are not congruent (not equal) or different in measure the polygon is known as a irregular polygon.

Above all of shapes are polygons. We notice that all the shapes are drawn with only straight lines and all the sides are connect. 

Not a polygon

In above shapes we notice that one shape is curved and other shape all the straight lines are not fully connected, so it can’t be called a polygon.