noun, plural i·co·sa·he·drons, i·co·sa·he·dra [ahy-koh-suh-hee-druh, ahy-kos-uh-] /aɪˌkoʊ səˈhi drə, aɪˌkɒs ə-/.
Origin of icosahedron
Examples from the Web for icosahedron
Historical Examples of 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.
noun plural -drons or -dra (-drə)
Word Origin 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).