A regular polygon is a geometric shape with all sides and angles equal. Common examples include the equilateral triangle, square, and regular hexagon. The number of sides determines the name of the polygon, such as pentagon for five sides and octagon for eight sides. Regular polygons can be inscribed in a circle, meaning all their vertices touch the circle's circumference. The center of this circle is also the center of the polygon. Regular polygons are often studied in geometry and have applications in various fields, including art, architecture, and nature.