The Golden Number is represented by the greek letter phi.
Many of the proportions of the Parthenon are alleged to exhibit the golden ratio.The Parthenon's facade as well as elements of its facade and elsewhere are said by some to be circumscribed by golden rectangles. Greek mathematician merely regarded that number as an interesting irrational number, in connection with the middle and extreme ratios. Its occurrence in regular pentagons and decagons was duly observed, as well as in the dodecahedron (a regular polyhedron whose twelve faces are regular pentagons).
In nature the golden ratio expressed in the arrangement of branches along the stems of plants and of veins in leaves. He extended his research to the skeletons of animals and the branchings of their veins and nerves, to the proportions of chemical compounds and the geometry of crystals.
Carlos Sanmartin and Miguel Angel Sastre 3ºB