Yes a hexagonal pyramid and a pentagonal prism
-5
A 3-D shape with 8 faces is an octahedron.
A point where three (or more) faces (sides) meet.
A dodecahedron has 12 identical pentagonal faces.
A cylinder.
This is an impossible shape. The only 3-d shape with 4 plane faces is a tetrahedron (triangular pyramid). While its base is a triangle, all of its other faces are also triangles and so cannot have parallel sides.
-4
No. A sphere is a three dimensional shape which has no polygonal faces. Similarly an ellipsoid, a torus, a paraboloid, hyperboloid etc are 3-D shapes with no polygonal faces.
The Euler characteristic for polyhedra then requires that thye shape has no vertices! And that means it cannot be a polyhedron. I suggest you count the faces and edges again.
a cylinder
a hexagonal pyramid is a 3-d shape with two hexagonal bases and three triangular faces!
They are straight lines where two plane faces of the shape meet. The definition is sometimes extended to curved lines where curved (3d) faces meet such as at the base of a cone.