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Johnson solid
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== Definition and background == {{multiple image | image1 = Elongated square gyrobicupola.png | image2 = Stella octangula.png | image3 = Partial cubic honeycomb.png | total_width = 500 | align = right | footer = Among these three polyhedra, only the first, the [[elongated square gyrobicupola]], is a Johnson solid. The second, the [[stella octangula]], is not [[Convex polyhedron|convex]], as some of its [[diagonal]]s (line segments connecting pairs of vertices) lie outside the shape. The third presents [[Coplanarity|coplanar]] faces. }} A Johnson solid is a [[convex polyhedron]] whose faces are all [[regular polygon]]s.{{r|diudea}} The convex polyhedron means as bounded intersections of finitely many [[Half-space (geometry)|half-spaces]], or as the [[convex hull]] of finitely many points.{{r|bk}} Although there is no restriction that any given regular polygon cannot be a face of a Johnson solid, some authors required that Johnson solids are not [[Uniform polyhedron|uniform]]. This means that a Johnson solid is not a [[Platonic solid]], [[Archimedean solid]], [[Prism (geometry)|prism]], or [[antiprism]].{{r|todesco|williams}} A convex polyhedron in which all faces are nearly regular, but some are not precisely regular, is known as a [[near-miss Johnson solid]].{{r|kaplan-hart}} The solids were named after the mathematicians [[Norman Johnson (mathematician)|Norman Johnson]] and [[Victor Zalgaller]].{{r|uehara}} {{harvtxt|Johnson|1966}} published a list including ninety-two solids—excluding the five Platonic solids, the thirteen Archimedean solids, the infinitely many uniform prisms, and the infinitely many uniform antiprisms—and gave them their names and numbers. He did not prove that there were only ninety-two, but he did conjecture that there were no others.{{r|johnson}} {{harvtxt|Zalgaller|1969}} proved that Johnson's list was complete.{{r|zalgaller}}
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