1) equilateral triangle
2) square and quadrilateral
3) regular hexagon

What is a Regular Polygon?
A regular polygon is a geometric figure with all sides and angles equal. This symmetry gives regular polygons distinct characteristics, making them unique in various mathematical and real-world applications. Regular polygons can be classified based on the number of sides they have.

Types of Regular Polygons
1. Regular Triangle (3 sides)
- Also known as an equilateral triangle, a regular triangle has three sides of equal length and three angles that each measure 60 degrees.
- It is the simplest form of a regular polygon, providing foundational insight into polygon properties.
2. Regular Quadrilateral (4 sides)
- Commonly known as a square, a regular quadrilateral has four equal sides and four right angles (90 degrees).
- It is widely used in architecture and design due to its symmetry and stability.
3. Regular Hexagon (6 sides)
- A regular hexagon consists of six equal-length sides and six angles, each measuring 120 degrees.
- This shape is often seen in nature, such as in honeycomb structures, due to its efficient tiling ability.

Conclusion
Regular polygons play a crucial role in geometry, architecture, and nature. Understanding their properties helps in various fields, from mathematics to art. Remember, the characteristics of regular polygons are defined by their equal sides and angles, contributing to their unique aesthetic and functional qualities.