- a solid figure having 20 faces.
Origin of icosahedron
Examples from the Web for icosahedron
The Icosahedron, having twenty equilateral triangles as faces.Bygone Beliefs
H. Stanley Redgrove
Associated words: vicenary, vigesimal, vigesimation, icosahedron.Putnam's Word Book
Louis A. Flemming
These give the solid angles of the tetrahedron, the octahedron and the icosahedron.
Within the earth's orbit inscribe an icosahedron: the sphere inscribed in it will be Venus's orbit.
Now, inscribe in the Earth an icosahedron, the circle inscribed in it will be Venus.
- a solid figure having 20 faces. The faces of a regular icosahedron are equilateral triangles
Word Origin and History for icosahedron
1560s, from Greek eikosahedron, neuter of eikosahedros, from eikosi "twenty" + -hedra "seat, base, chair, face of a geometric solid," from PIE root *sed- (1) "to sit" (see sedentary). Greek eikosi is from PIE *wikmti- "twenty," from *wi- "in half," hence "two" + (d)kmti-, from root *dekm- "ten" (see ten).
- A polyhedron having twenty faces.