A closed 2 dimensional shape is a polygon
If it is a 2 dimentional shape it is called an 'octadecagon'
it is a flat surface... the opposite of 3-dimentional.
If it were not for dark pigments 3 dimentional objects would appear as 2 dimentional or flat objects.
There is no such shape. If anyone can prove otherwise, I'd be grateful if they'd let me know.
A zero-dimensional shape is a point.
They are polyhedra.
It has length and width but no height
Yes, a flat cell is a flat cell that is 3 dimentional that are typically shown under a mircoscope or other (flat)
There are quite a few. Circles, squares, triangles...
a planet
Vertices are the points on any shape. For example, A 2-dimentional square has 4 vertices.