<h3>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. Circles and shapes that include curves are not polygons - a polygon, by definition, is made up of straight lines.</h3>
The first shape is a polygon while the second one is not.
1.A polygon is a flat, two-dimensional (2D) sides is fully closed. while, a non polygon shape is a shape that is not closed or doesn't have straight lines.
2. The thing that makes it a polygon or not is the opening/closing or the straight or non straight lines.