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1Created By
2What is Polyhedra?
- Polyhedra, like the example shown, is a
3-dimensional solid whose surfaces are flat. Many
everyday objects, such as a milk carton or filing
cabinet are polyhedral. A cup or a couch arent
polyhedral because some or all of their sides are
curved instead of being a flat plane.
3Criteria For Being a Polyhedra
- UNIFORM POLYHEDRA
- Each face is a regular polygon (all sides are the
same length and angles between sides are equal). - At any corner on the solid the same number of
polygons are joined together. - All the faces on it are identical to each other.
- It has no bumps, dents, spikes, etc.
- Archimedean Solids Polyhedra
- All faces are regular polygons.
- Around each corner are the same number of
polygons in the same order - The polyhedra has no bumps, spikes, dents, etc.
4Regular Uniform Polyhedra
5Regular Uniform Polyhedra Examples
- Although, my chart only shows the most common
Uniform Polyhedra, there are at least 120 of
them. The ones shown here are also four of the
more common, everyday Uniform Polyhedra. The blue
one is a regular dodecahedron, the red one below
it is a tetrahedron. The yellow one on the other
side is a hexahedron, and the red one below it is
a icosahedron.
6Archimedean Polyhedra
- These polyhedra often look like stained-glass
balls. One way of making these is to chop the
corners off of a Regular uniform polyhedra. The
cube and octahedron are Archimedeans too, because
the criteria for an Archimedean are more general
than those for a Regular uniform polyhedra.Some
are made by fitting triangles along a Regular
polyhedra, which shows that all polyhedra models
are mae from Regular Polyhedra. - The Archimedean shown here is constructed from
the hexahedron and octahedron, which are also
Archimedeans.
7Archimedean Polyhedra Examples
The duals of an Archimedean snub dodecahedron are
pictured here.These are created by fitting
triangles along the edges of a dodecahedron.
8Snub Polyhedra
- There are only 11 existing Regular Uniform
Snub Polyhedra.They are all also made from
Regular Uniform Polyhedra, but most Snubs are
much more complex. Many snubs are combined with
Archimedeans to make different typed of
polyhedra. They are made by adding points and
edges to the Regular polyhedras.
Shown above is a normal snub dodecadodecahedron
Shown above is a small snub icosicosidodecahedron
9Snub Polyhedra Examples
To the left you see a snub hexahedron. To the
right is a great dirhombicosidodecahedron
Above is a small retrosnub icosicosidodecahedron.
Above is a great inverted snub icosadodecahedron
10Why learn about Polyhedra?
- Polyhedra are beautiful to look at and may make
future math classes easier. - Also polyhedra is fun to make! There are several
ways to make models from using paper, to origami,
to computer graphics! - Go to htt//www.geocities.com
- to learn more about how to make polyhedra
models!