A polyhedron is any multi-faced solid. In order to know how many pairs, you need to know how many total faces.
There are 257 topologically different convex octahedra. Many of these will have no parallel faces. It can have four pairs of parallel faces.
none
Three pairs.
A rectangular prism has three pairs of parallel lines. The top and bottom faces are parallel to each other, the front and back faces are parallel, and the two side faces are parallel. This makes a total of three pairs of parallel lines in a rectangular prism.
A spherical polyhedron is a dodecahedron with 12 faces
A heptahedron is a seven-faced polyhedron. The number of pairs of parallel faces in a heptahedron can vary depending on its specific shape and configuration. For example, a regular heptahedron, such as a truncated triangular prism, may have pairs of parallel faces, while other irregular heptahedra may not have any. Therefore, the answer is not fixed and can range from zero to multiple pairs based on the specific heptahedron in question.
A cuboid has 3 pairs of parallel faces.
There are 257 topologically different convex octahedra. Many of these will have no parallel faces. It can have four pairs of parallel faces.
A rectangular prism has six faces, and each pair of opposite faces is parallel to each other. Therefore, a rectangular prism has three pairs of parallel faces.
3 pairs
3 pairs
21
Three pairs.
Three.
It can have one, two or three pairs of parallel faces.
A triangular based pyramid has zero pairs of parallel faces. In a triangular based pyramid, all three faces of the base are not parallel to the apex, which means there are no pairs of parallel faces in this type of shape.
There are infinitely many such polyhedra. A regular dodecahedron, for example.