just as you extract a cube out of a square, when you extract a 3d object from an octagon then it would have 16 vertices. it has 16 vertices, 10 faces 24 edges.
i think you were asking about a tesseract it is not a 3d shape but is 4d. just as a cube for a square,tesseract is for cube.
it looks like a smaller cube inside a larger cube where all corners of larger one are connected to smaller one respectively.
making this simple
join two points = line
join two parallel lines = square
join two parallel squares= cube
join two parallel cubes = tesseract.
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a triangle-based pyramid
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?
An octahedron is a closed 3-d shape with 8 polygonal faces. There are 257 topologically different convex octahedra. An octahedron can have 6 to 12 vertices.
The 3-d figure formed from regular pentagons is the dodecahedron which has 20 vertices.
The triangular prism is a 3-D shape that has a total of 5 faces. It also has 9 edges and 6 vertices.
-3
Something with 6 faces and 8 vertices
a triangle-based pyramid
cilinder
Square based pyramid
A triangular prism
It is a cuboid
There is no such thing as a polyhedon hexagon.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.
It is the icosahedron.
A hexadecahedron is a closed 3-d shape with 16 polygonal faces. There are almost 388 billion topologically different convex versions and, since none of these are regular, the term is ambiguous. The number of vertices will depend on which specific 16-hedron you have in mind.
-2
a shape that isn't 2-d and has 5 points eg. square based pyramid