Spirangle

File:Spirangle 3angle 5turn.jpg

3-angle spirangle or triangle spiral

File:Ulam-Spirale2.png

Ulam spiral in a 4-angle spirangle or rectangle spiral

File:Spirangle 7angle 8turn.jpg

7-angle spirangle or heptagon spiral

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70-angle spirangle

In geometry, a spirangle is a spiral polygonal chain. Spirangles are similar to spirals in that they expand from a center point as they grow larger, but they are made out of straight line segments, instead of curves. Spirangle vectographs are used in vision therapy to promote stereopsis and help resolve problems with hand–eye coordination.

Two-dimensional spirangles

A two-dimensional spirangle is an open figure consisting of a line bent into angles similar to a corresponding polygon. The spirangle can start at a center point, or a distance from the center, and has some number of turns around the center point.

Three-dimensional spirangles

Three-dimensional spirangles have layers that slant upward, progressively gaining height from the previous segment. This is similar to staircases in large buildings that turn at the top of each flight. The segments also may progressively lose an amount of length and resemble a pyramid.

Uses

• Ophthalmology — vectograms
• Electronics — printed inductors
• Architecture — 'spiral' staircases
• Jewelry — earrings, pendants
• Search algorithms — optimal scanning of a region of interest, for example a crime scene or a region of the celestial sphere

See also

• Turtle graphics

References

• Michael Scheiman & Bruce Wick (2013) Clinical Management of Binocular Vision, pp. 216, 256, 272, Wolters Kluwer, Fourth edition, .
• Jaime Aquilera & Roc Berenquer (2007) Design and Test of Integrated Inductors for RF Applications, p. 24, Springer Science & Business Media .

External links

• Colorado College field archeology site with a sample of ancient spirangle art