**3D Geometric Figures Names: A Comprehensive Guide**

**Introduction**

In mathematics, 3D geometric figures are an essential part of geometry. These figures have three dimensions, namely length, width, and height, which distinguish them from 2D shapes. In this article, we will explore the names of various 3D geometric figures, their definitions, and properties.

**1. Polyhedra**

A polyhedron is a 3D shape with flat faces and straight edges. There are many types of polyhedra, including:

**a. Tetrahedron**

A tetrahedron is a polyhedron with four triangular faces.

**b. Cube or Hexahedron**

A cube is a polyhedron with six square faces.

**c. Octahedron**

An octahedron is a polyhedron with eight triangular faces.

**d. Dodecahedron**

A dodecahedron is a polyhedron with twelve pentagonal faces.

**e. Icosahedron**

An icosahedron is a polyhedron with twenty triangular faces.

**2. Prisms**

A prism is a polyhedron with two identical faces that are polygons. The faces are connected by rectangular sides.

**a. Rectangular Prism**

A rectangular prism is a prism with rectangular faces.

**b. Triangular Prism**

A triangular prism is a prism with triangular faces.

**c. Pentagonal Prism**

A pentagonal prism is a prism with pentagonal faces.

**3. Pyramids**

A pyramid is a polyhedron with a polygonal base and triangular sides that meet at the apex.

**a. Square Pyramid**

A square pyramid is a pyramid with a square base.

**b. Triangular Pyramid**

A triangular pyramid is a pyramid with a triangular base.

**c. Pentagonal Pyramid**

A pentagonal pyramid is a pyramid with a pentagonal base.

**4. Cones and Cylinders**

**a. Cone**

A cone is a 3D shape with a circular base and a curved surface that tapers to a point.

**b. Cylinder**

A cylinder is a 3D shape with two parallel and circular bases connected by a curved surface.

**5. Spheres and Hemispheres**

**a. Sphere**

A sphere is a 3D shape that is symmetrical about its center and has a curved surface.

**b. Hemisphere**

A hemisphere is a 3D shape that is half of a sphere.

**Conclusion**

In this article, we have explored the names and definitions of various 3D geometric figures, including polyhedra, prisms, pyramids, cones, cylinders, spheres, and hemispheres. Understanding these shapes is crucial in mathematics and has applications in various fields such as architecture, engineering, and design.