What is the name of a six sided solid?

Answer 1

A six-sided solid is a hexahedron. There are seven topologically different convex types, among which are:

• triangular bipyramid,
  
• pentagonal pyramid,
  
• quadrilaterally faced hexahedron,
  
• tetragonal antiwedge (which can be left-handed or right-handed).

Answer 2

A cube or a cuboid are 3D solids that have 6 faces, 12 edges and 8 vertices

Answer 3

If it's a regular figure, it's a cube.