Date: 6/17/96 at 17:58:1 From: Anonymous Subject: Name of a Polyhedron I am taking a summer workshop entitled Kansas Middle Grades Mathematics project whose focus this year is geometry and stats. We were unable to obtain the name of the polyhedron that looks like the union of two tetrahedrons joined at their bases. Could you please tell us what this polyhedron is called? Thank you.
Date: 6/19/96 at 11:0:39 From: Doctor Chaos Subject: Re: Name of a Polyhedron Since the resulting figure has 6 faces, it can simply be called a hexahedron. But so too is a cube! I'm not sure if there is more that you can say to specify it other than to say, possibly, it is a trianglar hexahedron. A great book to have on the shelf is "Polyhedra Primer" by Peter Pearce and Susan Pearce, Dale Seymour Publications, ISBN 0-86651-419-8. -Doctor Chaos, The Math Forum Check out our web site! http://mathforum.org/dr.math/
Date: 6/21/96 at 12:59:27 From: Doctor Jodi Subject: Re: Name of a Polyhedron Although this self-intersecting polyhedron is one of my favorite shapes, I'd forgotten its name! I believe that it is called Kepler's Stella Octangula. You can find information by looking for Stella Octangula under S in the CRC Concise Encyclopedia of Mathematics: http://www.astro.virginia.edu/~eww6n/math/math.html and there are pictures at http://www.li.net/~george/virtual-polyhedra/compounds-info.html and at the top of the Math Forum Internet Mathematics Library: http://mathforum.org/library/ Key Curriculum Press also publishes a video and workbook about the shape. Good luck and let us know if you need any more help! -Doctor Jodi, The Math Forum Check out our web site! http://mathforum.org/dr.math/
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