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Secondary Magazine - Issue 27: Focus on

This page has been archived. The content was correct at the time of original publication, but is no longer updated.
Created on 04 February 2009 by ncetm_administrator
Updated on 27 April 2009 by ncetm_administrator

Secondary Magazine Issue 27

Focus on...three

3 was considered to be the first number by the Pythagoreans because it has a beginning, a middle and an end. Proclus also considered 3 to be the first number because it is increased more by multiplication than by addition (3 x 3 > 3 + 3). 

The number 3 appears many times in religion and mythology. There were trinities of gods in Greece, Egypt and Babylon while, in Christianity, God is a trinity. Greek mythology had 3 Fates, Furies, Graces, 3x3 Muses and Paris was required to choose between 3 goddesses.

A circle can be drawn through any 3 points not on a straight line. View the construction here.
3 is the second triangle number. In 1796 Gauss proved that every integer is the sum of at most 3 triangle numbers, writing in his diary "Heureka! num= Δ + Δ + Δ."
3 = 1! + 2! 
The volume of the smallest tetrahedron with integer edges and integer volume is 3.
3 is the only integer between e and π
In Vietnam it is bad luck to take a photograph with 3 people in it while, in many cultures, bad luck is said to come in threes.
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