**A geometric shape** is a complex of points, lines, or curves closed by one border. The basic shapes are square, triangle and circle.

Let’s have a look at the most common shapes using in 3d modeling.

###### Triangle (3 sides)

It is a simple geometric shape that includes three vertices connected by edges. 3D models consist are exactly from triangles. Even if the 3d model is from quad polygons, before the export, it should be converted to triangles. This process is called triangulation.

###### Quadrangle (4 sides)

Quadrangle is a type of polygon geometric figure that has only four sides. The main types of quadrangles are trapezoid, parallelogram, rectangle, square, rhombus.

###### Polygon (n-sides)

This category includes various geometric shapes, which consist of vertices connected by straight lines.

There are two types of polygons, **regular and irregular.**

**Regular** polygons include figures which have all angles and sides are equal, differently it is **irregular.**

Common regular polygons includes:

- Pentagons (5 sides);
- Hexagon (6 sides);
- Heptagon (7 sides);
- Octagons (8 sides);
- Nonagon (9 sides);
- Decagon (10 sides).