Concentrating on Polyhedra MathBitsNotebook.com Topical Outline | JrMath Outline | MathBits' Teacher Resources Terms of Use   Contact Person: Donna Roberts

Under the section "Area, Perimeter, Volume", we worked with polygons and polyhedra.

Polygon is a universal designation for 2-dimensional figures with line segments as their sides (such as triangles, rectangles, pentagons, etc.).

Polyhedron is a universal designation for 3-dimensional figures with sides composed of polygons (which will now extend beyond just triangles and quadrilaterals).

The three-dimensional figures with polygon faces are categorized as polyhedra.
A polyhedron has no curved surfaces.

If all of the sides are the same shape and size, the figure is called a regular polyhedron.

There are a total of five such regular polyhedra called the Platonic Solids,
after the ancient Greek philosopher Plato, in whose writings they first appeared.

Tetrahedron	Hexahedron	Octahedron	Dodecahedron	Icosahedron
4 triangle faces	6 square faces	8 triangle faces	12 pentagon faces	20 triangle faces

The hexahedron is also called a cube.

While there is no limit to the number of regular two-dimensional polygons,
there is a limit to the number of regular polyhedra! There are only five!

Topical Outline | JrMath Outline | MathBitsNotebook.com | MathBits' Teacher Resources
Terms of Use    Contact Person: Donna Roberts