If you've already taken a basic geometry course then I want you to think
back to that course and remember all of those extremely interesting shapes
you learned about, circles, squares, triangles, and all of
those other shapes. Now I want you to think about what was wrong with all
of those shapes. Give up? They are all two dimensional, and believe it
or not the world is three dimensional (if you don't believe me then check).
This web page will give you a brief glimpse at GEOMETRY IN
3D (sounds like an old B-Grade movie, doesn't it).
When we talked about polygons in our old geometry classes we were
referring to two dimensional shapes. Now that we're talking about three
dimensional shapes we use a different term, polyhedra. A polyhedra is any
three dimensional shape made up flat surfaces.
When we talked about Polygons we
used two axis in our Cartesian
Coordinate System. When talking about Polyhedra another axis is added, the Z axis. The Z axis runs
through the Origin toward you.
All polyhedra are made with combinations of polygons. A cube, for example,
is made up of six squares.