Geometry

All physical objects or things that exist in a state of matter are in a geometrical shape. Some are simple and others are complex.
Natural objects range from smooth/curved to straight and angled. All physical objects/bodies are made up of the primary solids the same way that all colors are made up of the primary three.

Basic two dimensional geometry

Circle - All round and curvy objects fall under this category.

Square - Rectangles, squares and other box like shapes fall under here.

Triangle - A three sided shape which is the basis of spikes or angled shapes.

Basic three dimensional geometry

Sphere - A perfectly round shape of any size.

Cube - A three dimensional square shape with six faces, and eight edges. You can elongate them to make a rectangle.

Pyramid - A flat base and edges which lead to a top, central point. The base can be circular, triangular, square or any other geometry.

Cylinder - An elongated circle with a flat top and bottom and rounded body. Barrel shaped.

Side notes

Universal index - Universal index