The 47th Problem of Euclid

A.K.A The Pythagorean Theorem

The 47th problem of Euclid (called that because Euclid included it in a book of numbered geometry problems) in which the sides are 3, 4, and 5 all whole numbers K is also known as “the Egyptian string trick.”

The “trick” is that you take a string and tie knots in it to divide it into 12 divisions, the two ends joining. The divisions must be correct and equal or this will not work.

Then get 3 sticks - thin ones, just strong enough to stick them into soft soil. Stab one stick in the ground and arrange a knot at the stick, stretch three divisions away from it in any direction and insert the second stick in the ground, then place the third stick so that it falls on the knot between the 4—part and the 5—part division. This forces the creation of a 3 - 4 - 5 right triangle. The angle between the 3 units and the 4 units is of necessity a square or right angle.

The ancient Egyptians used the string trick to create right angles when re—measuring their fields after the annual Nile floods washed out boundary markers. Their skill with this and other surveying methods led to the widely held but falsely belief that the Egyptians invented geometry geo=earth, metry = measuring.

Thales the Greek supposedly picked the string trick up while traveling in Egypt and took it back to Greece. Some say that the Greek mathematician and geometer Pythagoras, described in Masonic lectures as “our worthy brother,” also went to Egypt and learned it there on his own. In any case, it was he who supplied the PROOF that the angle formed by the 3 - 4- 5 triangle is invariably square and perfect. It is also said that he actually sacrificed a hecatomb, that is a sacrifice of one hundred bulls, which ranked as the highest kind of religious offering, upon completing the proof.

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