Created By: - PowerPoint PPT Presentation

1 / 10
About This Presentation
Title:

Created By:

Description:

The blue one is a regular dodecahedron, the red one below it is a tetrahedron. ... duals of an Archimedean snub dodecahedron are pictured here.These are created ... – PowerPoint PPT presentation

Number of Views:77
Avg rating:3.0/5.0
Slides: 11
Provided by: bsn8
Category:

less

Transcript and Presenter's Notes

Title: Created By:


1
Created By
2
What 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.

3
Criteria 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.

4
Regular Uniform Polyhedra
5
Regular 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.

6
Archimedean 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.

7
Archimedean Polyhedra Examples
The duals of an Archimedean snub dodecahedron are
pictured here.These are created by fitting
triangles along the edges of a dodecahedron.
8
Snub 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
9
Snub 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
10
Why 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!
Write a Comment
User Comments (0)
About PowerShow.com