- Snub disphenoid
Infobox Polyhedron with net

Polyhedron_Type=Johnson

J_{83}-**J**- J_{84}_{85}

Face_List=4+8triangle s

Edge_Count=18

Vertex_Count=8

Symmetry_Group="D_{2d}"| Vertex_List=4(3^{4})

4(3^{5})

Dual=-

Property_List=convex,deltahedron

Net_In

geometry , the**snub disphenoid**is one of theJohnson solid s ("J"_{84}). It is a three-dimensional solid that has onlyequilateral triangle s as faces, and is therefore adeltahedron . It is not aregular polyhedron because some vertices have four faces and others have five. It is one of the elementary Johnson solids that do not arise from "cut and paste" manipulations of the Platonic and Archimedean solids.The 92 Johnson solids were named and described by

Norman Johnson in1966 .It was called a

**Siamese dodecahedron**in the paper by Freudenthal and Waerden which first described it in 1947 in the set of convex deltahedra.**References*** * Freudenthal, H. and van der Waerden, B. L. "Over een bewering van Euclides". ("On an Assertion of Euclid") Simon Stevin 25, 115—128, 1947. (They showed that there are just 8 convex deltahedra. )

**External links***

** MathWorld | urlname=SnubDisphenoid | title=Snub disphenoid

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