A polyhedron (plural polyhedra or polyhedrons) is a geometric solid in three dimensions with flat faces and straight edges. The word polyhedron comes from the Classical Greek as poly- (stem of "many") + -edron (form of "base" "seat" or "face").

Defining a polyhedron as a solid bounded by flat faces and straight edges is not very precise and to a modern mathematician quite unsatisfactory. Grnbaum (1994 p. 43) observed "The Original Sin in the theory of polyhedra goes back to Euclid and through Kepler Poinsot Cauchy and many others ... in that at each stage ... the writers failed to define what are the 'polyhedra' ...." Since then rigorous definitions of "polyhedron" have been given within particular contexts. However such definitions are seldom compatible in other contexts. Contents 1 Basis for definition 2 Characteristics 2.1 Names of polyhedra 2.2 Edges 2.3 Euler characteristic 2.4 Orientability 2.5 Vertex figure 2.6 Duality 2.7 Volume 3 Traditional polyhedra 3.1 Symmetrical polyhedra 3.1.1 Uniform polyhedra and their duals 3.1.2 Noble polyhedra 3.1.3 Symmetry groups 3.2 Other polyhedra with regular faces 3.2.1 Equal regular faces 3.2.1.1 Deltahedra 3.2.2 Johnson solids 3.3 Other important families of polyhedra 3.3.1 Pyramids 3.3.2 Stellations and facettings 3.3.3 Zonohedra 3.3.4 Toroidal polyhedra 3.3.5 Compounds 3.3.6 Orthogonal polyhedra 4 Generalisations of polyhedra 4.1 Apeirohedra 4.2 Complex polyhedra 4.3 Curved polyhedra 4.3.1 Spherical polyhedra 4.3.2 Curved spacefilling polyhedra 4.4 General polyhedra 4.5 Hollow faced or skeletal polyhedra 5 Non-geometric polyhedra 5.1 Topological polyhedra 5.2 Abstract polyhedra 5.3 Polyhedra as graphs 6 History 6.1 Prehistory 6.2 Greeks 6.3 Chinese and Muslims 6.4 Renaissance 6.5 Star polyhedra 7 Polyhedra in nature 8 See also 9 References 10 Books on polyhedra 11 External links 11.1 General theory 11.2 Lists and databases of polyhedra 11.3 Software 11.4 Resources for making models and models for sale 11.5 Miscellaneous Basis for definition

Any polyhedron can be built up from different kinds of element or entity each associated with a different number of dimensions: 3 dimensions: The body is bounded by the faces and is usually the volume enclosed by them. 2 dimensions: A face is a polygon bounded by a circuit of edges and usually including the flat (plane) region inside the boundary. These polygonal faces together make up the polyhedral surface. 1 dimension: An edge joins one vertex to another and one face to another and is usually a line segment. The edges together make up the polyhedral skeleton. 0 dimensions: A vertex (plural vertices) is a corner point. -1 dimension: The null polytope is a kind of non-entity required by abstract theories.

More generally in mathematics and other disciplines "polyhedron" is used to refer to a variety of related constructs some geometric and others purely algebraic or abstract.

A defining characteristic of almost all kinds of polyhedra is that just two faces join along any common edge. This ensures that the polyhedral surface is continuously connected and does not end abruptly or split off in different directions.

A polyhedron is a 3-dimensional example of the more general polytope in any number of dimensions. Characteristics Names of polyhedra

Polyhedra are often named according to the number of faces. The naming system is again based on Classical Greek for example tetrahedron (4) pentahedron (5) hexahedron (6) heptahedron (7) triacontahedron (30) and so on.

Often this is qualified by a description of the kinds of faces present for example the Rhombic dodecahedron vs. the Pentagonal dodecahedron.

Other common names indicate that some operation has been performed on a simpler polyhedron for example the truncated cube looks like a cube with its corners cut off and has 14 faces (so it is also an example of a tetrakaidecahedron). Some special polyhedra have grown their own names over the years such as Miller's monster or the Szilassi polyhedron. Edges Edges have two important characteristics (unless the polyhedron is complex): An edge joins just two vertices. An edge joins just two faces. These two characteristics are dual to each other. Euler characteristic The Euler characteristic relates the number of vertices V edges E and faces F of a polyhedron: For a simply connected polyhedron 2. For a detailed discussion see Proofs and Refutations by Imre Lakatos. Orientability Some polyhedra such as all convex polyhedra have two distinct sides to their surface for example one side can consistently be coloured black and the other white. We say that the figure is orientable. But for some polyhedra this is not possible and the figure is said to be non-orientable. All polyhedra with odd-numbered Euler characteristic are non-orientable. A given figure with even < 2 may or may not be orientable. Vertex figure For every vertex one can define a vertex figure which describes the local structure of the figure around the vertex. If the vertex figure is a regular polygon then the vertex itself is said to be regular. Duality For every polyhedron there exists a dual polyhedron having: faces in place of the original's vertices and vice versa the same number of edges the same Euler characteristic and orientability The dual of a convex polyhedron can be obtained by the process of polar reciprocation. Volume This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2010) The volume of an orientable polyhedron can be calculated using the divergence theorem. Consider the vector field whose divergence is identically 1. The divergence theorem implies that the volume of any region is When is the region enclosed by a polyhedron since the faces of a polyhedron are planar and have piecewise constant normals this simplifies to where for the i'th face is any point on the face is the normal vector and Ai is area of the face. Traditional polyhedra A dodecahedron In geometry a polyhedron is traditionally a three-dimensional shape that is made up of a finite number of polygonal faces which are parts of planes; the faces meet in pairs along edges which are straight-line segments and the edges meet in points called vertices. Cubes prisms and pyramids are examples of polyhedra. The polyhedron surrounds a bounded volume in three-dimensional space; sometimes this interior volume is considered to be part of the polyhedron sometimes only the surface is considered and occasionally only the skeleton of edges. A polyhedron is said to be convex if its surface (comprising its faces edges and vertices) does not intersect itself and the line segment joining any two points of the polyhedron is contained in the interior or surface. Symmetrical polyhedra Many of the most studied polyhedra are highly symmetrical. Of course it is easy to distort such polyhedra so they are no longer symmetrical. But where a polyhedral name is given such as icosidodecahedron the most symmetrical geometry is almost always implied unless otherwise stated. Some of the most common names in particular are often used with "regular" in front or implied because for each there are different types which have little in common except for having the same number of faces. These are the triangular pyramid or tetrahedron cube or hexahedron octahedron dodecahedron and icosahedron: Polyhedra of the highest symmetries have all of some kind of element - faces edges and/or vertices within a single symmetry orbit. There are various classes of such polyhedra: Isogonal or Vertex-transitive if all vertices are the same in the sense that for any two vertices there exists a symmetry of the polyhedron mapping the first isometrically onto the second. Isotoxal or Edge-transitive if all edges are the same in the sense that for any two edges there exists a symmetry of the polyhedron mapping the first isometrically onto the second. Isohedral or Face-transitive if all faces are the same in the sense that for any two faces there exists a symmetry of the polyhedron mapping the first isometrically onto the second. Regular if it is vertex-transitive edge-transitive and face-transitive (this implies that every face is the same regular polygon; it also implies that every vertex is regular). Quasi-regular if it is vertex-transitive and edge-transitive (and hence has regular faces) but not face-transitive. A quasi-regular dual is face-transitive and edge-transitive (and hence every vertex is regular) but not vertex-transitive. Semi-regular if it is vertex-transitive but not edge-transitive and every face is a regular polygon. (This is one of several definitions of the term depending on author. Some definitions overlap with the quasi-regular class). A semi-regular dual is face-transitive but not vertex-transitive and every vertex is regular. Uniform if it is vertex-transitive and every face is a regular polygon i.e. it is regular quasi-regular or semi-regular. A uniform dual is face-transitive and has regular vertices but is not necessarily vertex-transitive). Noble if it is face-transitive and vertex-transitive (but not necessarily edge-transitive). The regular polyhedra are also noble; they are the only noble uniform polyhedra. A polyhedron can belong to the same overall symmetry group as one of higher symmetry but will have several groups of elements (for example faces) in different symmetry orbits. Uniform polyhedra and their duals Main article: Uniform polyhedron Uniform polyhedra are vertex-transitive and every face is a regular polygon. They may be regular quasi-regular or semi-regular and may be convex or starry. The uniform duals are face-transitive and every vertex figure is a regular polygon. Face-transitivity of a polyhedron corresponds to vertex-transitivity of the dual and conversely and edge-transitivity of a polyhedron corresponds to edge-transitivity of the dual. The dual of a regular polyhedron is also regular. The dual of a non-regular uniform polyhedron (called a Catalan solid if convex) has irregular faces. Each uniform polyhedron shares the same symmetry as its dual with the symmetries of faces and vertices simply swapped over. Because of this some authorities regard the duals as uniform too. But this idea is not held widely: a polyhedron and its symmetries are not the same thing. The uniform polyhedra and their duals are traditionally classified according to their degree of symmetry and whether they are convex or not. Convex uniform Convex uniform dual Star uniform Star uniform dual Regular Platonic solids Kepler-Poinsot polyhedra Quasiregular Archimedean solids Catalan solids (no special name) (no special name) Semiregular (no special name) (no special name) Prisms Dipyramids Star Prisms Star Dipyramids Antiprisms Trapezohedra Star Antiprisms Star Trapezohedra Noble polyhedra Main article: Noble polyhedron A noble polyhedron is both isohedral (equal-faced) and isogonal (equal-cornered). Besides the regular polyhedra there are many other examples. The dual of a noble polyhedron is also noble. Symmetry groups The polyhedral symmetry groups (using Schoenflies notation) are all point groups and include: T - chiral tetrahedral symmetry; the rotation group for a regular tetrahedron; order 12. Td - full tetrahedral symmetry; the symmetry group for a regular tetrahedron; order 24. Th - pyritohedral symmetry; order 24. The symmetry of a pyritohedron. O - chiral octahedral symmetry;the rotation group of the cube and octahedron; order 24. Oh - full octahedral symmetry; the symmetry group of the cube and octahedron; order 48. I - chiral icosahedral symmetry; the rotation group of the icosahedron and the dodecahedron; order 60. Ih - full icosahedral symmetry; the symmetry group of the icosahedron and the dodecahedron; order 120. Cnv - n-fold pyramidal symmetry Dnh - n-fold prismatic symmetry Dnv - n-fold antiprismatic symmetry Those with chiral symmetry do not have reflection symmetry and hence have two enantiomorphous forms which are reflections of each other. The snub Archimedean polyhedra have this property. Other polyhedra with regular faces Equal regular faces A few families of polyhedra where every face is the same kind of polygon: Deltahedra have equilateral triangles for faces. With regard to polyhedra whose faces are all squares: if coplanar faces are not allowed even if they are disconnected there is only the cube. Otherwise there is also the result of pasting six cubes to the sides of one all seven of the same size; it has 30 square faces (counting disconnected faces in the same plane as separate). This can be extended in one two or three directions: we can consider the union of arbitrarily many copies of these structures obtained by translations of (expressed in cube sizes) (200) (020) and/or (002) hence with each adjacent pair having one common cube. The result can be any connected set of cubes with positions (abc) with integers abc of which at most one is even. There is no special name for polyhedra whose faces are all equilateral pentagons or pentagrams. There are infinitely many of these but only one is convex: the dodecahedron. The rest are assembled by (pasting) combinations of the regular polyhedra described earlier: the dodecahedron the small stellated dodecahedron the great stellated dodecahedron and the great icosahedron. There exists no polyhedron whose faces are all identical and are regular polygons with six or more sides because the vertex of three regular hexagons defines a plane. (See infinite skew polyhedron for exceptions with zig-zagging vertex figures.) Deltahedra A deltahedron (plural deltahedra) is a polyhedron whose faces are all equilateral triangles. There are infinitely many deltahedra but only eight of these are convex: 3 regular convex polyhedra (3 of the Platonic solids) Tetrahedron Octahedron Icosahedron 5 non-uniform convex polyhedra (5 of the Johnson solids) Triangular dipyramid Pentagonal dipyramid Snub disphenoid Triaugmented triangular prism Gyroelongated square dipyramid Johnson solids Main article: Johnson solid Norman Johnson sought which convex non-uniform polyhedra had regular faces. In 1966 he published a list of 92 such solids gave them names and numbers and conjectured that there were no others. Victor Zalgaller proved in 1969 that the list of these Johnson solids was complete. Other important families of polyhedra Pyramids Main article: Pyramid (geometry) Pyramids include some of the most time-honoured and famous of all polyhedra. Stellations and facettings Main article: Stellation Stellation of a polyhedron is the process of extending the faces (within their planes) so that they meet to form a new polyhedron. It is the exact reciprocal to the process of facetting which is the process of removing parts of a polyhedron without creating any new vertices. Zonohedra Main article: Zonohedron A zonohedron is a convex polyhedron where every face is a polygon with inversion symmetry or equivalently symmetry under rotations through 180. Toroidal polyhedra Main article: Toroidal polyhedron A toroidal polyhedron is a polyhedron with an Euler characteristic of 0 or smaller representing a torus surface. Compounds Main article: Polyhedral compound Polyhedral compounds are formed as compounds of two or more polyhedra. These compounds often share the same vertices as other polyhedra and are often formed by stellation. Some are listed in the list of Wenninger polyhedron models. Orthogonal polyhedra An orthogonal polyhedron is one all of whose faces meet at right angles and all of whose edges are parallel to axes of a Cartesian coordinate system. Aside from a rectangular box orthogonal polyhedra are nonconvex. They are the 3D analogs of 2D orthogonal polygons also known as rectilinear polygons. Orthogonal polyhedra are used in computational geometry where their constrained structure has enabled advances on problems unsolved for arbitrary polyhedra for example unfolding the surface of a polyhedron to a polygonal net. Generalisations of polyhedra The name 'polyhedron' has come to be used for a variety of objects having similar structural properties to traditional polyhedra. Apeirohedra A classical polyhedral surface comprises finite bounded plane regions joined in pairs along edges. If such a surface extends indefinitely it is called an apeirohedron. Examples include: Tilings or tessellations of the plane. Sponge-like structures called infinite skew polyhedra. See also: Apeirogon - infinite regular polygon: Complex polyhedra A complex polyhedron is one which is constructed in complex Hilbert 3-space. This space has six dimensions: three real ones corresponding to ordinary space with each accompanied by an imaginary dimension. See for example Coxeter (1974). Curved polyhedra Some fields of study allow polyhedra to have curved faces and edges. Spherical polyhedra Main article: Spherical polyhedron The surface of a sphere may be divided by line segments into bounded regions to form a spherical polyhedron. Much of the theory of symmetrical polyhedra is most conveniently derived in this way. Spherical polyhedra have a long and respectable history: The first known man-made polyhedra are spherical polyhedra carved in stone. Poinsot used spherical polyhedra to discover the four regular star polyhedra. Coxeter used them to enumerate all but one of the uniform polyhedra. Some polyhedra such as hosohedra and dihedra exist only as spherical polyhedra and have no flat-faced analogue. Curved spacefilling polyhedra Two important types are: Bubbles in froths and foams such as Weaire-Phelan bubbles. Spacefilling forms used in architecture. See for example Pearce (1978). General polyhedra More recently mathematics has defined a polyhedron as a set in real affine (or Euclidean) space of any dimensional n that has flat sides. It may alternatively be defined as the union of a finite number of convex polyhedra where a convex polyhedron is any set that is the intersection of a finite number of half-spaces. It may be bounded or unbounded. In this meaning a polytope is a bounded polyhedron. Analytically such a convex polyhedron is expressed as the solution set for a system of linear inequalities. Defining polyhedra (and more generally polytopes) in this way provides a geometric perspective for problems in Linear programming. Many traditional polyhedral forms are general polyhedra. Other examples include: A quadrant in the plane. For instance the region of the cartesian plane consisting of all points above the horizontal axis and to the right of the vertical axis: ( x y ) : x 0 y 0 . Its sides are the two positive axes. An octant in Euclidean 3-space ( x y z ) : x 0 y 0 z 0 . A prism of infinite extent. For instance a doubly infinite square prism in 3-space consisting of a square in the xy-plane swept along the z-axis: ( x y z ) : 0 x 1 0 y 1 . Each cell in a Voronoi tessellation is a convex polyhedron. In the Voronoi tessellation of a set S the cell A corresponding to a point cS is bounded (hence a traditional polyhedron) when c lies in the interior of the convex hull of S and otherwise (when c lies on the boundary of the convex hull of S) A is unbounded. Hollow faced or skeletal polyhedra It is not necessary to fill in the face of a figure before we can call it a polyhedron. For example Leonardo da Vinci devised frame models of the regular solids which he drew for Pacioli's book Divina Proportione. In modern times Branko Grnbaum (1994) made a special study of this class of polyhedra in which he developed an early idea of abstract polyhedra. He defined a face as a cyclically ordered set of vertices and allowed faces to be skew as well as planar. Non-geometric polyhedra Various mathematical constructs have been found to have properties also present in traditional polyhedra. Topological polyhedra A topological polytope is a topological space given along with a specific decomposition into shapes that are topologically equivalent to convex polytopes and that are attached to each other in a regular way. Such a figure is called simplicial if each of its regions is a simplex i.e. in an n-dimensional space each region has n+1 vertices. The dual of a simplicial polytope is called simple. Similarly a widely studied class of polytopes (polyhedra) is that of cubical polyhedra when the basic building block is an n-dimensional cube. Abstract polyhedra An abstract polyhedron is a partially ordered set (poset) of elements whose partial ordering obeys certain rules. Theories differ in detail but essentially the elements of the set correspond to the body faces edges and vertices of the polyhedron. The empty set corresponds to the null polytope or nullitope which has a dimensionality of 1. These posets belong to the larger family of abstract polytopes in any number of dimensions. Polyhedra as graphs Any polyhedron gives rise to a graph or skeleton with corresponding vertices and edges. Thus graph terminology and properties can be applied to polyhedra. For example: Due to Steinitz theorem convex polyhedra are in one-to-one correspondence with 3-connected planar graphs. The tetrahedron gives rise to a complete graph (K4). It is the only polyhedron to do so. The octahedron gives rise to a strongly regular graph because adjacent vertices always have two common neighbors and non-adjacent vertices have four. The Archimedean solids give rise to regular graphs: 7 of the Archimedean solids are of degree 3 4 of degree 4 and the remaining 2 are chiral pairs of degree 5. History Prehistory Stones carved in shapes showing the symmetries of various polyhedra have been found in Scotland and may be as much as 4000 years old. These stones show not only the form of various symmetrical polyehdra but also the relations of duality amongst some of them (that is that the centres of the faces of the cube gives the vertices of an octahedron and so on). Examples of these stones are on display in the John Evans room of the Ashmolean Museum at Oxford University. It is impossible to know why these objects were made or how the sculptor gained the inspiration for them. Other polyhedra have of course made their mark in architecture - cubes and cuboids being obvious examples with the earliest four-sided pyramids of ancient Egypt also dating from the Stone Age. The Etruscans preceded the Greeks in their awareness of at least some of the regular polyhedra as evidenced by the discovery near Padua (in Northern Italy) in the late 19th century of a dodecahedron made of soapstone and dating back more than 2500 years (Lindemann 1987). Pyritohedric crystals are found in northern Italycitation needed. Greeks The earliest known written records of these shapes come from Classical Greek authors who also gave the first known mathematical description of them. The earlier Greeks were interested primarily in the convex regular polyhedra which came to be known as the Platonic solids. Pythagoras knew at least three of them and Theaetetus (circa 417 B. C.) described all five. Eventually Euclid described their construction in his Elements. Later Archimedes expanded his study to the convex uniform polyhedra which now bear his name. His original work is lost and his solids come down to us through Pappus. Chinese and Muslims By 236 AD in China Liu Hui was describing the dissection of the cube into its characteristic tetrahedron (orthoscheme) and related solids using assemblages of these solids as the basis for calculating volumes of earth to be moved during engineering excavations. After the end of the Classical era Islamic scholars continued to take the Greek knowledge forward. The 9th century scholar Thabit ibn Qurra gave formulae for calculating the volumes of polyhedra such as truncated pyramids. Then in the 10th century Abu'l Wafa described the convex regular and quasiregular spherical polyhedra. Renaissance As with other areas of Greek thought maintained and enhanced by Islamic scholars Western interest in polyhedra revived during the Italian Renaissance. Artists constructed skeletal polyhedra depicting them from life as a part of their investigations into perspective. Several appear in marquetry panels of the period. Piero della Francesca gave the first written description of direct geometrical construction of such perspective views of polyhedra. Leonardo da Vinci made skeletal models of several polyhedra and drew illustrations of them for a book by Pacioli. A painting by an anonymous artist of Pacioli and a pupli depicts a glass rhombicuboctahedron half-filled with water. As the Renaissance spread beyond Italy later artists such as Wenzel Jamnitzer Drer and others also depicted polyhedra of various kinds many of them novel in imaginative etchings. Star polyhedra For almost 2000 years the concept of a polyhedron as a convex solid had remained as developed by the ancient Greek mathematicians. During the Renaissance star forms were discovered. A marble tarsia in the floor of St. Mark's Basilica Venice depicts a stellated dodecahedron. Artists such as Wenzel Jamnitzer delighted in depicting novel star-like forms of increasing complexity. Johannes Kepler realised that star polygons typically pentagrams could be used to build star polyhedra. Some of these star polyhedra may have been discovered before Kepler's time but he was the first to recognise that they could be considered "regular" if one removed the restriction that regular polytopes be convex. Later Louis Poinsot realised that star vertex figures (circuits around each corner) can also be used and discovered the remaining two regular star polyhedra. Cauchy proved Poinsot's list complete and Cayley gave them their accepted English names: (Kepler's) the small stellated dodecahedron and great stellated dodecahedron and (Poinsot's) the great icosahedron and great dodecahedron. Collectively they are called the Kepler-Poinsot polyhedra. The Kepler-Poinsot polyhedra may be constructed from the Platonic solids by a process called stellation. Most stellations are not regular. The study of stellations of the Platonic solids was given a big push by H. S. M. Coxeter and others in 1938 with the now famous paper The 59 icosahedra. This work has recently been re-published (Coxeter 1999). The reciprocal process to stellation is called facetting (or faceting). Every stellation of one polytope is dual or reciprocal to some facetting of the dual polytope. The regular star polyhedra can also be obtained by facetting the Platonic solids. Bridge 1974 listed the simpler facettings of the dodecahedron and reciprocated them to discover a stellation of the icosahedron that was missing from the famous "59". More have been discovered since and the story is not yet ended. See also: Regular polyhedron: History Regular polytope: History of discovery. Polyhedra in nature For natural occurrences of regular polyhedra see Regular polyhedron: Regular polyhedra in nature. Irregular polyhedra appear in nature as crystals. See also Wikimedia Commons has media related to: Polyhedron Look up polyhedron in Wiktionary the free dictionary. Antiprism Archimedean solid Bipyramid Conway polyhedron notation (a notation for describing construction of polyhedra) Defect Deltahedron Deltohedron Escher Flexible polyhedra Johnson solid Kepler-Poinsot polyhedra List of polyhedral images Near-miss Johnson solid Net (polyhedron) Platonic solid Polychoron (4 dimensional analogues to polyhedra) Polyhedral compound Polyhedron models Prism Semiregular polyhedron Schlegel diagram Spidron Tessellation Trapezohedron Uniform polyhedron Waterman polyhedron Zonohedron Extension of a polyhedron References Coxeter H.S.M.; Regular complex Polytopes CUP (1974). Cromwell P.;Polyhedra CUP hbk (1997) pbk. (1999). Grnbaum B.; Polyhedra with Hollow Faces Proc of NATO-ASI Conference on Polytopes ... etc. (Toronto 1993) ed T. Bisztriczky et al. Kluwer Academic (1994) pp. 4370. Grnbaum B.; Are your polyhedra the same as my polyhedra Discrete and comput. geom: the Goodman-Pollack festschrift ed. Aronov et al. Springer (2003) pp. 461488. (pdf) Pearce P.; Structure in nature is a strategy for design MIT (1978) Books on polyhedra Main article: List of books about polyhedra External links General theory Weisstein Eric W. "Polyhedron" from MathWorld. Polyhedra Pages uniform solution for uniform polyhedra by Dr. Zvi Har'El Symmetry Crystals and Polyhedra Symmetrohedra: Polyhedra from Symmetric Placement of Regular Polygons Lists and databases of polyhedra The Uniform Polyhedra Virtual Reality Polyhedra - The Encyclopedia of Polyhedra Polyhedra and Pyramids Interactive 3D polyhedra in Java Electronic Geometry Models - Contains a peer reviewed selection of polyhedra with unusual properties. Origami Polyhedra - Models made with Modular Origami Polyhedra Collection - Various virtual and physical polyhedra models. Polyhedra plaited with paper strips - Polyhedra models constructed without use of glue. Rotatable polyhedron models (uses Javascript) Rotatable self-intersecting polyhedra (uses Java) Polyhedron Models - Virtual polyhedra Java Applets for Visualizing Polyhedra - Systematically explicit formulae given! Software A Plethora of Polyhedra An interactive and free collection of polyhedra in JAVA. Features includes nets planar sections duals truncations and stellations of more than 300 polyhedra. Stella: Polyhedron Navigator - Software for exploring polyhedra and printing nets for their physical construction. Includes uniform polyhedra stellations compounds Johnson solids etc. World of Polyhedra - Comprehensive polyhedra in flash applet showing vertices and edges (but not shaded faces) Hyperspace Star Polytope Slicer - Explorer java applet includes a variety of 3d viewer options. HEDRON Polyhedron modelling software Uniform Polyhedra Java Applets with sources Resources for making models and models for sale Making Polyhedra Paper Models of Polyhedra Free nets of polyhedra Paper Models of Uniform (and other) Polyhedra Kits and instructions for making models of polyhedra out of bamboo Polyhedra software die-cast models & posters Simple instructions for building over 30 paper polyhedra Kits to print out cut and fold into various polyhedra openSCAD. Free cross-platform software for programmers. Polyhedra are just one of the things you can model. The openSCAD User Manual is also available. Miscellaneous PictureSpice - A site that lets you make polyhedra with your own uploaded pictures. Lattice Polyhedra v d ePolyhedra Dihedron Tetrahedron Pentahedron Hexahedron Heptahedron Octahedron Decahedron Dodecahedron Tetradecahedron Icosahedron v d ePolyhedron navigator Platonic solids (regular) tetrahedron  cube  octahedron  dodecahedron  icosahedron Archimedean solids (Semiregular/Uniform) truncated tetrahedron  cuboctahedron  truncated cube  truncated octahedron  rhombicuboctahedron  truncated cuboctahedron  snub cube  icosidodecahedron  truncated dodecahedron  truncated icosahedron  rhombicosidodecahedron  truncated icosidodecahedron  snub dodecahedron Catalan solids (Dual semiregular) triakis tetrahedron  rhombic dodecahedron  triakis octahedron  tetrakis cube  deltoidal icositetrahedron  disdyakis dodecahedron  pentagonal icositetrahedron  rhombic triacontahedron  triakis icosahedron  pentakis dodecahedron  deltoidal hexecontahedron  disdyakis triacontahedron  pentagonal hexecontahedron Dihedral regular dihedron  hosohedron Dihedral uniform prisms  antiprisms Duals of dihedral uniform bipyramids  trapezohedra Dihedral others pyramids  truncated trapezohedra   gyroelongated bipyramid   cupola   bicupola   pyramidal frusta Degenerate polyhedra are in italics. v d eFundamental convex regular and uniform polytopes in dimensions 210 Family An BCn Dn E6 / E7 / E8 / F4 / G2 Hn Regular polygon Triangle Square Hexagon Pentagon Uniform polyhedron Tetrahedron Octahedron Cube Demicube Dodecahedron Icosahedron Uniform polychoron 5-cell 16-cell Tesseract Demitesseract 24-cell 120-cell 600-cell Uniform 5-polytope 5-simplex 5-orthoplex 5-cube 5-demicube Uniform 6-polytope 6-simplex 6-orthoplex 6-cube 6-demicube 122 221 Uniform 7-polytope 7-simplex 7-orthoplex 7-cube 7-demicube 132 231 321 Uniform 8-polytope 8-simplex 8-orthoplex 8-cube 8-demicube 142 241 421 Uniform 9-polytope 9-simplex 9-orthoplex 9-cube 9-demicube Uniform 10-polytope 10-simplex 10-orthoplex 10-cube 10-demicube n-polytopes n-simplex n-orthoplex n-hypercube n-demicube Topics: Polytope families Regular polytope List of regular polytopes