The Fibonacci Sequence, The Golden Rectangle and Architecture pt.1. In 1202 Leonardo Fibonacci was famously investigating rabbit reproduction and made note of a sequence that is now know as his namesake – The Fibonacci sequence. The sequence is 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, et cetera. It is derived by adding each number to the previous, e.g. 1 + 1 = 2, 1+2 3, 2 + 3 = 5. Plant leaves as they spiral around a stem, called (phyllotaxis), in some cases follow a mathematical rhythm of 1.618. The same spiraling numberical rhythm seen on the skin of a pineapple as well as the seed head arrangement of the sunflower, and the base of a pinecone. In geometrical terms if a rectangle is drawn with one side equal to 1 and its perpendicular side represented as 1.618, a desirable shape emerges. In 1876 Gustov Fechner did a study that determined that people visually preferred the shape to other rectangles. It’s thought that the ratio may have been used as early as the Egyptians in the creation of the great pyramids. In fact, It’s probably true. Based on measurements of the Pyramid at Giza the hypotenuse almost precisely matches the number phi or 1.618. It’s also thought that Andrea Palladio employed the golden ratio proportions. This is his Villa Rotonda outside Vincensa in northern Italy. Even the modern architect Le Corbusier used the proportions in his modular man study and, most likely, to design his Unite d Habitation in Marseilles France. If you’re looking for more videos about the Golden Rectangle and architecture check out Doug's other Channel, How to Architect Premium.