2006-09-19 11:50:25 · 8 answers · asked by ted1ba1r 1 in Science & Mathematics ➔ Mathematics
a twenty-sided 3D figure
2006-09-19 11:52:38 · answer #1 · answered by MollyMAM 6 · 0⤊ 1⤋
A dodecahedron is any polyhedron with twelve faces, but usually a regular dodecahedron is meant: a Platonic solid composed of twelve regular pentagonal faces, with three meeting at each vertex. It has twenty vertices and thirty edges. Its dual polyhedron is the icosahedron.
Cartesian coordinates
The following Cartesian coordinates define the vertices of a dodecahedron centered at the origin:
(±1, ±1, ±1)
(0, ±1/Ï, ±Ï)
(±1/Ï, ±Ï, 0)
(±Ï, 0, ±1/Ï)
where Ï = (1+â5)/2 is the golden ratio (also written Ï). The side length is 2/Ï = -1 + â5.
The dihedral angle of a dodecahedron is 2arctan(Ï) or approximately 116.565 degrees.
2006-09-19 18:59:23 · answer #2 · answered by Cute Is What I Aim For 4 · 0⤊ 0⤋
it is a polyhedron with 12 faces but usually a regular dodecahedron is meant a plalonic solid composed of 12 reular pentagonal faces meeting at each vertex. It has 20 vertices and 30 edges
2006-09-19 19:59:43 · answer #3 · answered by Dreana S 2 · 0⤊ 0⤋
A 20 sided figure is called a icosahedron from the Greek word for 20.
A 12 sided figure is called a dodecahedron from the Greek word for 12.
http://mathforum.org/dr.math/faq/faq.polygon.names.html has more names for different sided polygons and figures.
2006-09-19 18:56:41 · answer #4 · answered by Anonymous · 2⤊ 0⤋
Yep, 12 sided
2006-09-19 18:53:39 · answer #5 · answered by Anonymous · 1⤊ 0⤋
20 sided 3d shape
2006-09-19 18:52:28 · answer #6 · answered by ice_purple969 4 · 0⤊ 1⤋
it is a polygon with 20 sides.
2006-09-19 18:53:39 · answer #7 · answered by Anonymous · 0⤊ 1⤋
type it on google and you will find out.
my guess is a 20 sided polygon.
2006-09-19 18:52:12 · answer #8 · answered by s_e_e 4 · 0⤊ 1⤋