How many bases does a triangular pyramid have?
https://www.mathsisfun.com/geometry/triangular-pyramid.html
It looks to me as though they are all bases.
so the lateral area would be zero?
A triangular pyramid, also known as a tetrahedron, is a polyhedron with four triangular faces. To determine the number of bases, we need to understand that a base is a face that lies on the bottom or bottommost portion of the shape. Since there are no specific requirements for this defining characteristic, it can be subjective.
In a tetrahedron, none of the triangular faces is inherently considered a "base." However, for practical purposes, we can consider any one of the triangular faces as a base. So, by convention, a triangular pyramid has one base.
It's important to note that different sources or contexts may have different conventions. For instance, in some mathematical discussions or calculations, triangular pyramids may not be referred to as having a base at all. Therefore, when dealing with this shape, it's always advisable to define and clarify what is being considered as the base, if any, to avoid any confusion.