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Webster 1913 Edition
Icosahedron
Iˊco-sa-he′dron
,Noun.
[Gr. [GREEK]; [GREEK] twenty + [GREEK] seat, base, fr. [GREEK] to sit.]
(Geom.)
A solid bounded by twenty sides or faces.
Regular icosahedron
, one of the five regular polyhedrons, bounded by twenty equilateral triangules. Five triangles meet to form each solid angle of the polyhedron.
Webster 1828 Edition
Icosahedron
ICOSAHE'DRON
,Noun.
In geometry, a regular solid, consisting of twenty triangular pyramids, whose vertices meet in the center of a sphere supposed to circumscribe it, and therefore have their highths and bases equal.