6
That would be 2 times the number of sides in the base. For example, a triangular pyramid has 6 edges. A rectangular pyramid has 8 edges. An octagonal pyramid has 16 edges.
"Octagonal" is an adjective. That is not enough information. Is it an octagonal prism, octagonal pyramid, octagonal bipyramid or something else? Each one would lead to a different answer.
6
If by "side" you mean face, you might be referring to a heptagonal pyramid (a pyramid with eight faces).If by "side" you mean edge, you might be referring to a tetragonal pyramid (a pyramid with eight edges).Or, if you mean it has an eight-sided base, your answer would be an octagonal pyramid (a pyramid with an eight-sides base).
That's going to depend on what shape you're building, which, as far as I can see, you neglected to mention.
If side refers to 'face', then the pyramid would be a quadrilateral pyramid with 8 edges. If side refers to the base of the pyramid, it would be a pentagonal pyramid with 10 edges.
The answer will depend on what the shape is. And since you have not bothered to share that crucial bit of information, I cannot provide a more useful answer.
Depends on the pyramid. A pyramid with a square (or quadrilateral) base would indeed have 8 edges, but a pyramid can have any other polygon as a base.Depends on the pyramid. A pyramid with a square (or quadrilateral) base would indeed have 8 edges, but a pyramid can have any other polygon as a base.Depends on the pyramid. A pyramid with a square (or quadrilateral) base would indeed have 8 edges, but a pyramid can have any other polygon as a base.Depends on the pyramid. A pyramid with a square (or quadrilateral) base would indeed have 8 edges, but a pyramid can have any other polygon as a base.
6 of them
16
A pyramid with 18 edges would be called a nonagonal pyramid. A prism with 18 edges is called a hexagonal prism.