Golden Rectangle:

Also known as the "Golden Ratio" "Golden Section" and "Golden Mean" From the Greeks, the Golden Rectangle -- a mathematical formula of great visual elegance -- is arrived at by bissecting a square and using the diagonal of one half of the square as a radius to extend the dimensions of the square to become a "Golden Rectangle." In the proportion arrived at, a:b = c:a.

The Greeks used the "Golden Mean" to design what they built, from the parthenon  to the floor plans of temples.

Jim Tolpin puts it elegantly:

"When designing temples for their gods, the craftsmen of ancient Greece used a proportional system that pleased the eye and nourished the soul."

 

Sources: Donis A Dondis, A Primer of Visual Literacy, Cambridge: MIT Press,, 1973; Matila Ghyka, The Geometry of Art and Life  New York: Dover, 1977 (Ghyka's book  is dedicated to a discussion of the concept, with the second chapter giving details about the concept's origin); R J DeCristoforo, Woodworking Mistakes and Solutions, New York: Sterling, 1996, pages 135-138. (No preview available on Google Print.); Jim Tolpin, Working Wood: A Complete Bench-Top Reference Worcester, MA: Davis Publications, 1997, page 120 (Using just words and pencil diagrams, in a single page, Tolpin captures the essence of the concept); Paul Harrel, "Designing Along the Grain", Practical Design: Solutions and Strategies -- Key Advice for Sound Construction from Fine Woodworking  Newtown, CT: Taunton, 2000; Mario Livio, The Golden Ratio New York: Broadway Books, 2002.