It depends on the 3d shape.
It is not a 3D shape.
2d
A heptagon is not a 3D shape. It is a seven sided shape. It could be designed on 3D software if necessary.
A cylinder is a 3d shape because you can see the in side of it.
It depends on the 3d shape.
It is not a 3D shape.
A camera is a 3D shape. A photograph is a 2D projection of a 3D shape onto a 2D shape.
a pyramid is a 3D shape :)
is a square a 3d shape
Paper is a 3D object.
2d
A heptagon is not a 3D shape. It is a seven sided shape. It could be designed on 3D software if necessary.
A shape in 3D is a polygon. Poly=many and gon=shape.
Many 3d shapes have a corner.
A 3d shape can have infinite sides
A 12 sided 3D shape is a dodecahedron.