Which of the following is a characteristic of a regular polygon?

A regular polygon is defined by having specific geometric properties that distinguish it from irregular polygons. One of the key characteristics is that all its sides are congruent, meaning they are of equal length. This congruence ensures that when you measure each side, the measurements will be identical, contributing to the overall symmetry of the shape.

In addition, a regular polygon has all its interior angles equal. This equality arises naturally from the congruence of the sides, producing a uniform and balanced appearance. The regularity of these characteristics is what gives a regular polygon its name, indicating that it adheres to a strict set of rules regarding side length and angle measurement.

On the other hand, a regular polygon possesses a fixed number of sides based on its type, so it does not have a variable number of sides. Furthermore, the vertices of a regular polygon do not lie on a straight line; instead, they create closed shapes such as triangles, squares, or pentagons, where each vertex connects with the others to form the polygon itself.

Thus, the distinct property of all sides being congruent is crucial to defining what makes a polygon regular, making it the correct characteristic to identify in this context.