**Generative Geometry**

## The
archetypal circle and square can geometrically generate many forms. Ancient
cultures recognized these forms and relationships as essential and sacred, a
metaphor of universal order. The circle and square in the act of self-division give
us three generative roots: the square roots of 2, 3, and 5 (figs. 1A and 1B of
"Generative Geometry"). These root relationships are all that are
necessary to form the five regular (Platonic) solids that are the basis for all
volumetric forms (fig. 1C). Also, 2, 3, and 5 are the only numbers required to
divide the octave into musical scales.

Geometric Properties of Plane Figures
The area of the surface is best found by adding together the areas of all the faces. |

The area of a right cylindrical surface = perimeter of base x length of elements (average length if other base is oblique).

The area of a right conical surface = perimeter of base x 1/2 length of elements.

There
is no simple rule for the area of an oblique conical surface, or for a
cylindrical one where neither base is perpendicular to the elements. The best
method is to construct a development, as if making a paper model, and measure
its area by one of the methods given in the "Triangular and Circular
Geometry" information.

**Volumes and Surfaces of Typical Solids**

__Triangular and Circular Geometry__

**Oblique Triangles**

**Right Triangle**

**Arcs**

**Cords**