Golden ratio

The golden ratio is used in all kinds of art and design to create attractive shapes. It is called ‘golden’ because it has special qualities. The most important uses of it in art are to make golden rectangles and to divide up compositions on golden sections. Some artists and designers work these out exactly but other just do what ‘looks right’ and come to the same result. You find them in paintings, in the design of cars, in the design of typefaces and in architecture, as well as in natural forms such as plants.

The golden ratio is based on the number 1.618, often symbolised by the Greek letter ‘phi’.  

• When a picture is square its height and its width are the same, so they have a ratio of 1 to 1. Instead, a golden rectangle is one where the long side is 1.618 times the short side – a ratio of 1.618 to 1.
• The golden section of a line is the point where the ratio of the longer part to the shorter part is 1.618. (Interestingly, the ratio of the longer part to the whole line is 1.618 as well.)

This is the same ratio that you find in the Fibonacci sequence, where each number is roughly 1.618 times the one before it (topic 9).