In maths (geometry) a tetrahedron, also called a triangular pyramid. This is the pyramid which is also a polyhedron and it is composed of four triangular faces, along with that there are six straight edges as well as four vertex corners also. The structure of the **tetrahedron** is known to be the simplest structure of all the normal convex polyhedra. And along with that, it is the only one that has less than 5 faces.

The structure of the tetrahedron is also called the three-dimensional structure case of the more general concept of a simplex of Euclidean and we can say that because of this it is also called a 3-simplex.

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**Tetrahedron **

The structure of a regular tetrahedron is a tetrahedron in which all the other four faces are equilateral triangles. It is defined as one of the five regular Platonic solids that have been in existence since antiquity.

In a tetrahedron that is regular, all the faces are of the same shape and size which is also called congruent and all edges are of the same length.

The figure or structure of a honeycomb is one that is a tessellation. There are some of the tetrahedra that are not regular and these generally include the Schläfli or thoscheme and the Hill tetrahedron.

**More About Tetrahedron**

The above-mentioned structure of tetrahedra is one kind of pyramid only. This is a pyramid which is a polyhedron with a flat base of polygon and faces that are triangular. These all are connecting the base to a similar or we can say a common point. In the case of a tetrahedron, we can easily observe that the base is a triangle that any of the four faces can be considered the base. So the geometrical structure of a tetrahedron is also called a pyramid that is triangular.

Like all the other convex polyhedra there is a tetrahedron that can also be folded from a single sheet of paper. That has two such kinds of nets.

- For any structure of tetrahedron there usually exists a sphere which is known as the circumsphere. This circumsphere is the one on which all four vertices lie and along with that another sphere that is the insphere tangent to the faces of the tetrahedron.
- Now we can ask: is the figure of the tetrahedron a regular polygon or not?

The relation between the is very simple for example we can say that a triangle is a polygon itself. The figure of a tetrahedron is also a polyhedron with 4 triangles as its faces.

**What is Regular Polygon?**

In the geometry of euclidean a polygon that is regular is a polygon that is equiangular, that is we can say whose all angles are equal in measure. Along with that, it is equilateral which means all sides have the same length. The polygons which are regular may be either a star or a convex. We can also notice that the limit of a sequence is of regular polygons with a number in increasing order of sides nearly a circle. In it, if the area or the perimeter is fixed or say a regular then that is effectively a line that is straight if the length of the edge is also fixed.

**Properties of Regular Polygon**

These properties usually apply to all the polygons that are regular whether they are star or convex.

- A regular polygon that is also known as the n-sided has symmetry which is rotational symmetry and it is of order n.
- In a
**regular polygon****,**all the vertices lie on a common circle that the circumscribed circle. - Together with the property of sides that are equal-length, it implies that every polygon which is regular also has an inscribed circle or we can say incircle.

This incircle is known as the tangent to each and every side at the midpoint. Thus a polygon that is said to be a regular polygon is generally a tangential polygon. You may learn this topic in an interesting way from Cuemath.