A Platonic Solid is a 3D shape where: 1  each face is the same regular polygon. 2  the same number of polygons meet at each vertex (corner)
https://www.mathsisfun.com/platonic_solids.html
The Icosahedron. The icosahedron has 12 vertices, 20 faces and 30 sides. It is one of the most interesting and useful of all polyhedra. Buckminster Fuller based his designs of geodesic domes around the icosahedron. The icosahedron is built around the pentagon and the golden section.
http://www.kjmaclean.com/Geometry/Icosahedron.html
Icosahedron is one of the five Platonic solids. In geometry, an icosahedron is a regular polyhedron with 20 identical equilateral triangular faces, 30 sides and 12 vertices. Icosahedron or regular icosahedron is the regular polyhedron and Platonic solid having 12 polyhedron vertices, 30 polyhedron edges, and 20 equivalent equilateral triangle faces.
http://www.mathcaptain.com/geometry/icosahedron.html
A icosahedron is a regular polyhedron composed of 20 equally sized equilateral triangles, 30 sides and 12 vertices, 30 sides and 5 number of concurrent edges. The volume and surface area of the icosahedron is given below. The surface area, A, and the volume, V, of a regular icosahedron of edge length 'a' are:
http://www.mathcaptain.com/geometry/icosahedron.html
The regular icosahedron (often simply called the icosahedron) is the regular polyhedron and Platonic solid having 12 polyhedron vertices, 30 polyhedron edges, and 20 equivalent equilateral triangle faces, . SEE ALSO: Regular Icosahedron.
http://mathworld.wolfram.com/Icosahedron.html
The regular icosahedron (often simply called the icosahedron) is the regular polyhedron and Platonic solid having 12 polyhedron vertices, 30 polyhedron edges, and 20 equivalent equilateral triangle faces, . From MathWorld--A Wolfram Web Resource.
http://mathworld.wolfram.com/Icosahedron.html
The icosahedron has 20 triangular faces. Any icosahedron will have 20T faces, 12 pentamers and 10(T-1) hexamers. The triangulation number can be graphically determined with the following drawing arranged from Caspar and Klug (1963).
https://s10.lite.msu.edu/res/msu/botonl/b_online/library/multimedia-virology/triangulation.html
There are only five platonic solids. The Platonic Solids. For each solid we have two printable nets (with and without tabs). You can make models with them! Print them on a piece of card, cut them out, tape the edges, and you will have your own platonic solids. 3 triangles meet at each vertex.
https://www.mathsisfun.com/platonic_solids.html
In the first two cases the icosahedron class is P=1, for the latter case the class is P=3. For any other number there is a left/right asymmetry. In these cases for a given triangulation number there exists 2 possibilities for the position of point M and the corresponding icosahedra are mirror images of one another.
https://s10.lite.msu.edu/res/msu/botonl/b_online/library/multimedia-virology/triangulation.html
Quasi-equivalence: T number and P number. The icosahedron has 2,3 and 5-fold symmetry. Each of the 20 facets of a T=1 icosahedron have a real icosahedral 3-fold symmetry. Hence each triangle can be subdivied into 3 equal portions.
https://s10.lite.msu.edu/res/msu/botonl/b_online/library/multimedia-virology/triangulation.html
icosahedron number of triangle faces
In icosahedron, the number of triangle faces is 20. In icosahedron, there are 20 triangle faces.