Find all for which it is possible to find a convex polyhedron with all faces congruent such that each face has another face parallel to it.
Solution
Since for each face there is another parallel to it, must be even. For , attach two congruent regular pyramids with lateral faces by its bases. For , attach two congruent regular pyramids with lateral faces and twist one of them. Possible coordinates for the vertices of this solid are , and .
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