A) A regular hexagonal prism is a 2D hexagon extended 'up' into the third dimension directly along the normal of the plane formed by the two extant axes.
This then means all the six straight faces extending up in the new axis are rectangles.
Prisms are just named on their base end, in the above a hexagon.
Every slice perpendicular to the base-face is a replica of this base face, anywhere up the prism.
In every regular prism (regular base shape) there is a central thread running up the prism in the third dimension, starting base-face to the other end's extruded-face.
If I have a prism, and I look at a slice half-way up it, and then extend each of the vertices outward from the point in the centre of the slice's hexagon, i.e. from the point at the thread intersecting the slice to each of the slice's vertices - this makes a bigger hexagon than the base and end hexagons.
Each of the six rectanglar faces is now split into two trapezoids.
Do these classes of 3D shape (forms of prism) then have a name?
B) I have a similar question about pyramids.
For example take a Rectangular Square Pyramid; then take another; then stick the two square bases together - this shape has a special name, an Octahedron.
Is there a generic name for shape-based-pyramids stuck together of any shape? For example, two Hexagonal Pyramids form a ... ?
For (B): I think I have heard the term "Dipyramid", so another name for an Octahedron would be a 'Square Dipyramid', then the Hexagonal one would be a 'Hexagonal Dipyramid'; able to be extended to any named pyramidal base-shape.
For (A): Could then the general term for the mid-height extruded prisms be a 'diprism'? So my example is then a Hexagonal Diprism?
Are there 'proper' terms for these shapes I cannot find?
In a way, all dipyramids are formed in a similar way to my (A) hexagonal example -> take two points; join with a central thread; half-way up extend in the two-dimensional plane normal to the thread ONE particular shape (a square for the Octahedron), and the dipyramid is then formed with the square in the middle having its face-normals facing the points --> ergo it makes sense somewhat that both classes of shape (double-joined pyramids and middle-bulged prisms) share a similar naming convention.
As a side-note, contracting the mid-height hexagon in (A) to a point just gives two Hexagonal Pyramids point-aligned and touching, mirroring each other opposite their face-plane.