hexagonal prism
In geometry, the hexagonal prism is a prism with hexagonal base. This polyhedron has 8 faces, 18 edges, and 12 vertices. Since it has 8 faces, it is an octahedron. However, the term octahedron is primarily used to refer to the regular octahedron, which has eight triangular faces.
https://en.wikipedia.org/wiki/Hexagonal_prism#/media/File:Hexagonal_prism.png
Add 8 to both sides. 21 - 3d = 0 Add 3d to both sides. 21 = 3d Divide both sides by 3. 7 = d Plug 7 into the original. 13 - 21 = -8 It checks.
8 sides because a normal square has 4 times it by 2 is 8
octagon-2D Octahedron-3D
A cube has:- 6 sides 12 edges 8 corners
A 3d shape can have infinite sides
Add 8 to both sides. 21 - 3d = 0 Add 3d to both sides. 21 = 3d Divide both sides by 3. 7 = d Plug 7 into the original. 13 - 21 = -8 It checks.
8 sides because a normal square has 4 times it by 2 is 8
Edges are sides in terms of 2D shapes but they are the place where two sides of a 3D shape meet ie. the sharp edge that runs between corners
An octahedron is a 3D shape with 8 sides.
octagon-2D Octahedron-3D
square based pyramid
A cube has:- 6 sides 12 edges 8 corners
A 3d shape can have infinite sides
12 Sides.... A 3d Square is a cube!!
An octahedron.An octahedron.An octahedron.An octahedron.
9 3d sides
3D shapes have edges, sides, and intersecting points