A 3-D shape that has 8 faces is a hexagonal prism. This is a shape that is formed on a hexagon-shaped base.
An octahedron is a closed 3-d shape with 8 polygonal faces. There are 257 topologically different convex octahedra. They can have faces which are triangles, quadrilaterals, pentagons, hexagons or heptagons.
Octagon. * * * * * An octagon is 2-dimensional. The regular 3-d shape (all faces the same) is the octahedron, but a hexagonal prism also has 8 faces.
8 * * * * * There is no 3-D shape made from regular hexagons. The previous answer may refer to a hexagonal prism. But that is not a 3-D hexagon: the shape has two hexagonal faces and six rectangles - not just hexagons.
A dodecahedron is a 3-d shape with 12 faces that are regular pentagons.
Pyramid
A 3-D shape with 8 faces is an octahedron.
A truncated tetrahedron.
There is no 3-d shape with 4 and 1 = 5 triangular faces.
Tetra = four. It is a 3-d shape with 4 faces.
A tetrahedron is the smallest possible polyhedron: a closed 3-d shape with polygonal faces. It has 4 triangular faces, 4 vertices and 6 edges.
A tetrahedron is the smallest possible polyhedron: a closed 3-d shape with polygonal faces. It has 4 triangular faces, 4 vertices and 6 edges.
A 3-d shape with 6 equal faces is a cube. It has 6 squares as it's faces. A 3-d shape with 6 equal faces and only 2 squares is a rectangular prism. It has 2 squares and 4 other rectangles (squares are rectangles too) as it's faces.
tetrahedron
octahedron
All of them.
A tetrahedron is the smallest possible polyhedron: a closed 3-d shape with polygonal faces. It has 4 triangular faces, 4 vertices and 6 edges.