A hexagonal pyramid has only and also 7 faces.
A triangular pyramid has 5 planes. * * * * * In fact, a triangular pyramid is also known as a tetrahedron and as its name suggests, it has 4 plane faces.
The bottom, or base of a pyramid would count as a face is you were finding out surface area.
You could have GIZA or a pyramid. Also a square house if your really desperate.
A square based pyramid is the best name. It is a pentahedron, but that could also refer to a pyramid on any quadrilateral base and so the name is far less informative.
hexahedron
a hexahedron.
You could classify a regular tetrahedron, which is a platonic sold, as a cone.
It is a tetrahedron that is a triangular based pyramid
Regular: and there are only five of them. They are also knows as the platonic solids.
It is known that in the Neolithic period, platonic solids were carved out of stone. The Greeks also studied them quite a bit. Of course, Plato also studied them and they are named after him. So it is not easy to answer the question how were they discovered, but it seems they were stone carvings.
A pyramid has the solid quadrilateral pyramid solid shape.However there are also pyramids with geometrical polyhedra/platonic solid shapes of tetrahedron.
Time changes even the classics. the present-day 5 Platonic solids- thought to be indispensible in teaching how to draw in perspective are: Sphere, Cube, Cone, Cylinder, and Pyramid ( or tetrahedron, another term for the same thing) the originals were somewhat different. the concept originated with Plato, who also gave us the Atlantis legend in 360 BC. ( Box your compass- BC- a good memory jog). The originals were quite different- see, I believe , the Mathematical Carnival by Martin Gardner.
Geometric relationsThe cube is unique among the Platonic solids for being able to tile Euclidean space regularly. It is also unique among the Platonic solids in having faces with an even number of sides and, consequently, it is the only member of that group that is a zonohedron (every face has point symmetry).The cube can be cut into 6 identical square pyramids. If these square pyramids are then attached to the faces of a second cube, a rhombic dodecahedronis obtained.
9 sided "barrel dice" and 9 sided "parachute" style dice do exist. They are essentially cylinders with 9 numbered faces and rounded ends (so the die can't land end-on), or an ice-cream cone shape with 9 facets and one rounded end (again, so it can't land end-on). These are the only "fair" dice that can have 9 sides. There is no "platonic solid" that has 9 equal sides. Polyhedral Dice (The platonic solids you would generally encounter playing table-top rpgs like Dungeons and Dragons) generally only come in the following sizes: 4, 6, 8, 12, & 20. 10 sided dice are also available that are "fair", but are not platonic solids.
None.
There are five regular polyhedra, also known as the Platonic solids. They are three-dimensional shapes where all of the faces are made up of the same regular polygon.They are:Tetrahedron with four faces (this one is like a pyramid, but with an equilateral triangle for the base and all of the faces)Cube with six faces (all squares)Octahedron with eight faces (all equilateral triangles)Dodecahedron with 12 faces (all regular pentagons)Icosahedron with 20 faces (all equilateral triangles)A square pyramid (like the Egyptian pyramids) is not a regular polyhedron, because it has two different types of regular polygons for faces.