Icosahedron
If the faces are flat, it's a line.
Isosceles TetrahedronA solid with four faces is a tetrahedron. Each of the faces is a triangle. If all the triangles are congruent, you have an isosceles tetrahedron.
a cylinder a cylinder
A solid figure with twenty faces is called an Icosahedron.
Icosahedron
A cube has six square faces.
A vertex is the name of a corner on a solid where three or more faces meet (plural = vertices).
If the faces are flat, it's a line.
The solid with 12 equal faces is a dodecahedron. A dodecahedron has 12 equal pentagon surfaces.
an edge
a triangular prism.
triangular prism
A cone
a vortex
An edge.
18-gon is its name.