How many vertices does a hexagon solid have?

Answer 1

There is no such thing as a hexagonal solid. A regular hexagon will tessellate and so it forms a plane (2-D) surface, not a 3-D shape.

A 3-D shape with six faces is a hexahedron and this could be a triangular bipyramid with 5 vertices, a parallelepiped with 8 vertices, a pentagonal pyramid with six vertices. There are also other possible shapes.

Answer 2

A solid hexagon cannot exist.