5.
Penta means five, therefore (penta = 5).
A pentagonal pyramid has 10 edges.
6 faces, 10 edges and 6 vertices if it has a pentagonal base
Six Three edges on base Three edges on side
The edges for a rectangular pyramid is 8.
It has 12 edges.
four
A pyramid with an n-sided base will have n + 1 vertices, n + 1 faces, and 2n edges.
There is no simple way. You cannot go by the name - which can refer to the number of faces. You can have different shapes with the same number of faces. The following are all examples of a hexahedron (six faces): triangular dipyramid (9 edges), pentagonal prism (10 edges), rectangular prism (12 edges). One contributor has suggested it might be easier to count the faces and vertices (corners). Add the two numbers and then subtract 2. *This will work if the shape has been simplified as much as it can be. The 2 is only valid if there are no holes in the shape. For example, a pentagonal prism: 6 faces, 6 vertices. Sum = 12. Subtract 2 = 10. A pentagonal pyramid has 10 edges.
A tetrahedron triangular based pyramid has 6 edges, 4 faces and 4 vertices
0 corners, infinity edges and 1 face
A tetrahedron triangular based pyramid has 6 edges, 4 faces and 4 vertices
A triangular based pyramid has 4 faces, 6 edges and 4 vertices