Golden Ratio
In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. The figure on the right illustrates the geometric relationship.
Phi is also used as a symbol for the Golden Ratio and on other occasions in math and science. This use is separately encoded as the Unicode glyph ϕ.
The golden ratio 1.618033988749894848204586834... in mathematics, art, and architecture.
The golden ratio also is called the golden mean or golden section. Other names include extreme and mean ratio, medial section, divine proportion, divine section , golden proportion, golden cut, and golden number.[1]