an OCTAGON
A U shaped room has 8 edges on the floor, 8 on the roof and 8 vertical edges, making 24
That's an impossible shape. No shape can have only 2 edges.
A shape with more than 8 edges is a nonagon, which has 9 edges. Other examples include a decagon with 10 edges, or further polygons like a dodecagon with 12 edges, and so on. In three-dimensional geometry, a shape like a dodecahedron has 30 edges. Thus, there are many shapes that can fit this criterion.
It is a cuboid that has 8 vertices, 12 edges and 6 faces
An octohedron
A shape with 8 sides is an octagon
an octogon
A U shaped room has 8 edges on the floor, 8 on the roof and 8 vertical edges, making 24
the answer is a square pyramid
An Octagon
If that shape is a polygon then its named an octagon.
That's an impossible shape. No shape can have only 2 edges.
A cube.
there are none
The question is ambiguous. An octagon is a 2-dimensional shape with 8 edges and 8 vertices. Does a 3-D octagonal shape mean one with 8 edges or 8 faces or vertices, or faces which are 2d octagons?
A shape with more than 8 edges is a nonagon, which has 9 edges. Other examples include a decagon with 10 edges, or further polygons like a dodecagon with 12 edges, and so on. In three-dimensional geometry, a shape like a dodecahedron has 30 edges. Thus, there are many shapes that can fit this criterion.
It is a cuboid that has 8 vertices, 12 edges and 6 faces