The easiest way to think of vertices on a 3-dimensional object is to think of vertices as corners. Now, which 3-dimensional object has 8 corners? That would be a trapezoidal prism.
rectangular prism
It is a cube.
A cube
A cube
A pyramid with a square base.
rectangular prism
It is a cube.
A cube
A cube
A pyramid with a square base.
It is an octagon
It is an 8 sided octagon
A cube or a cuboid would fit the given description
A rectangular prism and a cube! :)
A rectangular prism.
An octagon is a 2-dimensional (flat) figure, with 8 sides and 8 vertices.
A square based pyramid would fit the given description