An octahedron is a closed 3-d shape with 8 polygonal faces. There are 257 topologically different convex octahedra. Some of these have no parallel sides whereas a right hexagonal prism has 3 quartet of parallel sides and one sextet.
An octahedron has 7 perpendicular lines.
None
None
Infinite
14
2
2
1 pair
parellel lines
No
Yes.
Parellel lines