A polygon is a 2-dimensional figure, a solid is 3-dimensional.
true
a cube
It is not a solid figure because an icosagon is a polygon with 20 sides
a pyramid
No. A polygon is a plane figure - i.e. it is 2-dimensional A cone is a solid figure - i.e it is 3-dimensional
Such a figure is a pyramid.
octagonal prism (i guessed)
face
A polygon is a many sided 2-dimensional figure, and thus could never be "solid" Alternatively, it could be "one face that is a polygon". In that case the solid could be like a pyramid that morphs into a cone or a part-sphere. The base would be the one polygon, the other face would not.
Polygon
A pyramid.