Because the interior angles are not an even fraction of 360o ( they are 140o) and thus they cannot form a circle.
Interior angles of triangles (60), squares (90) and hexagons (120) are and thus these shapes can tile the plane.
Yes
If it's a regular hexagon it will tessellate.
nonagon
Because nonagon means 9 sides
Not a regular nonagon.
Only if all nine sides are the same length.
A nonagon is a 2D shape so you cannot make a 3D nonagon!
A nonagon has nine sides.
Nonagon.
"nonagon" is not a prefix.
A nonagon
A nonagon.