The golden Number.

-The golden number is represented by the Greedl letterφ or Φ, is an irrational number: 2

-In mathematics and  arts, two quantities are in the golden ratio if the ratio of the sum of the quantities to the larger quantity is equal to the ratio of the larger quantity to the smaller one. The figure on the right illustrates the geometric relationship. Expressed algebraically:

-The golden ratio has been used since Egyptian times for the construction of buildings, though, are the Greeks use: who exploited it to maximum use in all facets of art. Here are some examples of this:

+The first known use of the golden ratio appears in building the pyramid of Cheops, dating from 2600 BC.

+An example of a golden rectangle in art is the elevation of the Greek Parthenon.

-The golden ratio arises from the division into two of a segmentstoring the following proportions: total length a + b is the longestsegm.ento is accommodative to the shorter segment b.