Icosahedron
The (general) icosahedron is a 20-faced polyhedron (where icos- derives from the Greek word for "twenty" and -hedron comes
from the Indo-European word for "seat"). Examples illustrated above include
the decagonal dipyramid, elongated
triangular gyrobicupola (Johnson solid 👁 J_(36)
), elongated
triangular orthobicupola (👁 J_(35)
), gyroelongated
triangular cupola (👁 J_(22)
),
Jessen's orthogonal icosahedron,
metabiaugmented dodecahedron (👁 J_(60)
), nonagonal antiprism, parabiaugmented
dodecahedron (👁 J_(59)
),
18-gonal prism, 19-gonal pyramid, regular icosahedron, and rhombic
icosahedron.
The regular icosahedron (often simply called "the" icosahedron) is the regular polyhedron
and Platonic solid 👁 P_3
having 12 polyhedron vertices,
30 polyhedron edges, and 20 equivalent equilateral
triangle faces, 👁 20{3}
.
See also
Regular Icosahedron Explore this topic in the MathWorld classroomExplore with Wolfram|Alpha
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Cite this as:
Weisstein, Eric W. "Icosahedron." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Icosahedron.html