## Fig. -1.

In Euclidean geometric space no polygon

can have less than 3 angles.

In spherical geometry a polygon

can have as little as 2 angles.

In Fig. -1:

At (a)

a miniature globe is shown and on it

2 straight lines are shown,

starting at the North Pole and

ending at the South Pole.

These lines enclose

2 90° angles, 1 at each pole.

Thus these lines form

a polygon having 2 angles,

known as a “Digon”.

It also poses the question:

is there such an entity as

a “digonal spiral”?

At (b)

a slice contained between

these 2 lines & the polar centerline

has been cut away leaving

2 perfectly flat surfaces 90° apart.

At (c)

the 2 spokes of the putative digonal spiral are

shown on the flat surfaces, 1 from each corner,

with their ends abutted against the center and

stretched around it to abut against each other.

At (d)

the 2 webs are added to the spokes.

At (e)

the 90° cavity -and the digon-

have been opened up to 180°,

resulting in a digon with

2 180° angles &

2 enclosed coplanar surfaces.

At (f)

the digonal spiral has been rotated to

horizontalize the spokes.

Due to (e) & (f) the digonal spiral

can now be presented in plan view,

as shown in Fig. -2.

Given the method by which it is generated

this spiral can be called the “Diporal Spiral”.

There are other similarly generated polar spirals.