Irregular Polygons are closed shapes which we often come across in the study of Plane Geometry. While regular polygons are always convex, irregular polygons can be a convex or a concave Polygon. Even though it appears that regular Polygons were perfect in shape, in real life we generally come across only irregular Polygons. Fields, Yards, Housing plots and many interior spaces are found to be of irregular polygon shapes. And it is often required to find the measures related to these shapes. This makes the study of irregular polygons necessary in Geometry.

The fact that a polygon can be partitioned into smaller polygons helps us in dividing an irregular polygons into a number of regular and irregular polygons. As the areas of these smaller polygons can be calculated using formulas, the area of an irregular polygon can also be arrived as a sum.

A Regular Polygon is defined to be a convex polygon where all the sides are congruent and all the angles or congruent.

Hence an irregular polygon is a polygon which is not regular. That is either all sides are not congruent or all angles are not congruent or both the conditions for regular polygon fail. Regular Polygons can be either convex or concave.

A Polygon is termed to be irregular if:

All sides are not congruent
All angles are not congruent
both the sides are not congruent and the angles are not congruent.

Let us look into few examples of irregular polygons.