icosahedron
noun
ico·sa·he·dron
(ˌ)ī-ˌkō-sə-ˈhē-drən 
-ˌkä-
plural icosahedrons or icosahedra
(ˌ)ī-ˌkō-sə-ˈhē-drə
-ˌkä-
: a polyhedron having 20 faces
Examples of icosahedron in a Sentence
Recent Examples on the Web
But many famous convex polyhedra — for instance the dodecahedron, or the truncated icosahedron, the shape that forms a soccer ball — are highly symmetric and difficult to analyze.
—
Erica Klarreich, Quanta Magazine, 24 Oct. 2025
Fuller started by building icosahedral domes but realized that larger structures containing more than twenty triangles could be made by taking the primary triangles and systematically assembling them into larger triangles, each of which could then be used to build an icosahedron.
—Judith Graf, The New York Review of Books, 1 Dec. 2022
The symmetry group of the quasicrystal is the same as that of the regular 20-sided solid known as an icosahedron, and the chemistry is given by the formula Si61Cu30Ca7Fe2.
—David Bressan, Forbes, 18 May 2021
One popular design is based on the mathematical structure of an icosahedron, a three-dimensional shape built from equilateral triangles.
—Eugenia Cheng, WSJ, 19 Nov. 2020
For that kind of math, the icosahedron was the ideal random number generator.
—William Herkewitz, Popular Mechanics, 1 Sep. 2019
The arrangement of rotations which leave the objects looking unchanged is the same as that of a regular icosahedron.
—George Hart, Scientific American, 22 Mar. 2013
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Erica Klarreich, Quanta Magazine, 24 Oct. 2025
Fuller started by building icosahedral domes but realized that larger structures containing more than twenty triangles could be made by taking the primary triangles and systematically assembling them into larger triangles, each of which could then be used to build an icosahedron.
—Judith Graf, The New York Review of Books, 1 Dec. 2022
The symmetry group of the quasicrystal is the same as that of the regular 20-sided solid known as an icosahedron, and the chemistry is given by the formula Si61Cu30Ca7Fe2.
—David Bressan, Forbes, 18 May 2021
One popular design is based on the mathematical structure of an icosahedron, a three-dimensional shape built from equilateral triangles.
—Eugenia Cheng, WSJ, 19 Nov. 2020
For that kind of math, the icosahedron was the ideal random number generator.
—William Herkewitz, Popular Mechanics, 1 Sep. 2019
The arrangement of rotations which leave the objects looking unchanged is the same as that of a regular icosahedron.
—George Hart, Scientific American, 22 Mar. 2013
Cite this Entry
“Icosahedron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/icosahedron. Accessed 13 Nov. 2025.
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