Triangles are 2d. Pyramids are 3d.
4
3
piramid
Eight
A pyramid (not piramid) is a generic term used to describe a polyhedron with a polygonal base and a number of triangles rising from that base to meet at an apex. A pyramid whose base is a polygon with n-sides (or vertices) has n+1 faces, n+1 vertices and 2n edges, where n ≥ 3.
There are 6 triangles in an octagon
10 triangles
10 triangles make a decagon
27 triangles make up an Icosihenagon
depends on the side of the triangles?
5.3 H