because it felt like it
A regular icosahedron has 20 faces (equilateral triangles), 30 edges and 12 vertices.
Their faces are equilateral triangles.
In geometry, an icosahedron is a regular polyhedron with 20 identical equilateral triangular faces.
Icosahedron
An Icosahedron.
A tetrahedron (4 faces) and an icosahedron (20).
In geometry, an icosahedron is a regular polyhedron with 20 identical equilateral triangular faces.
An icosahedron.
Tetrahedron, icosahedron.
Icosahedron is a polyhedron having twenty plane faces.
There is no such thing as a 3d triangle. A 3d shape which has only equilateral triangular faces can be a tetrahedron which has 4 faces or an icosahedron which has 20.