Is there a 3-D object with 3 faces? What is it called?
Hello,Good answer; but I was asking about flat surfaces. I understand that no such object exists. Is there a theorem about the min. number of flat surfaces that a 3-D object must have?
Darn, I was going to say that. Furthermore, when you consider the convex hull of this polytope, the convex hull can extend in two dimensions; but there needs to be at least one point above the plane of the other points in order to achieve what you desire. Otherwise it's simply a 2-dimensional face.Hello,
What you are thinking of is a 3 dimensional (convex) polytope. I assume you mean codimension 1 faces (i.e. 2 dimensional faces). Technically, edges and vertices are also called faces. In this case, the minimum number of faces is 4 (a tetrahedron). In general, an n dimensional polytope needs to have at least n+1 facets.
A cylinder has 3 sides if you include it's curved surface. Both 'sides' of a mobius strip are curved into each other so you only have 2 sides. With only flat surfaces I think n+1 is the minimum number.Of course - the edges are connected - dumb of me.
So it's possible to have a 2 sided 3D object but not a 3 sided one ?