Fibonnacci was a mathematician who devised a formula of proportion. It is a series of numbers which is the same ratio found in natural patterns such as sunflower heads, pinecones, leaves and trees.
The series is based on the sum of the two previous numbers, ie 0+1=1, 1+1=2, 1+2=3, 2+3=5, 3+5=8, 5+8=13, 8+13=21 etc.
The Golden Section comprises 2 small squares, side by side. Next to this is another square that is the same width as both tiny squares. Moving around the centre in a spiralling direction, is another square which is the same size as the previous two, and so on. By drawing a diagonal line across the shapes (see 2077) a spiral is formed, as can be found in fossils and shells.
The formula creates a series of rectangles in a beautifully proportioned arrangement and makes a good formula for designing with simple shapes.