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Septvaginta Duarus Planus Vacuus

George W. Hart

This cherry orb (with a cherry and holly sign, and brass wire) is Septvaginta Duarus Planus Vacuus. The geometric form consists of sixty "kites" and twenty equilateral triangles.  I call the underlying form a "propello-icosahedron" because if you look at each triangle, you will see it is surrounded by three kites which spiral like a propellor.  There are 20 of these groups (arranged as in an icosahedron) in the complete form.  The kites are particularly interesting because they have three equal face angles.

Although in the style of Leonardo da Vinci's polyhedron models, this is a new polyhedron, not previously described in the mathematical literature.  As Leonardo's drawings of polyhedra in this open-face style were important in the Renaissance for disseminating knowledge of geometry, I chose this style for this first model of this polyhedron.

copyright 1999, George W. Hart