# What's up ici? Issue 3 - Page 14

MATHS CORNER

The number of gold,

also called golden ratio is an irrational number, represented by the Greek letter phi in honour to the Greek sculptor Phidias.The equation is expressed as follows:

The golden ratio is the numerical value of the proportion there is between two segments of a straight line: a and b (a being longer than b) which satisfies the following relationship:

* The total length, the sum of the two segments a and b, is the largest segment, so this segment is at the lowest b, written as this algebraic equation:

DEFINITION

The drawing of a man's body in a pentagram suggests relationships to the golden ratio.

The first to make a formal study of the Golden Number was Euclide, who defined it as follows:

"A straight line is said to have been cut in extreme and mean ratio when, as the whole line is to the greater segment, so is the greater to the lesser"

Euclide also showed that this number cannot be described as the ratio of two integers, it is an irrational number.

Plato lived before Euclide but he also studied the golden ratio. He describes five possible regular solids (the Platonic solids: the tetrahedron, cube, octahedron, dodecahedron, and icosahedron), some of which are related to the golden ratio

The Egyptians seemed to be well acquainted with the golden ratio

HISTORY

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