It all depends on what kind of polygon it is. It may have no congruent sides or all congruent sides.
A regular polygon is a polygon with congruent sides and interior angles.
It is an equilateral polygon. It is not a regular polygon. For the polygon to be regular, it is not enough for the sides to be congruent: all the angles need to be congruent as well.
It's equilateral !!! A polygon with all sides congruent is equilateral.
A regular polygon
a regular polygon
It is a regular polygon
It would be an irregular polygon that has not congruent sides and angles
That's a regular polygon.
Any regular polygon
An irregular polygon
It is a regular polygon