History of Trigonometry
July 20, 2022

Trigonometry, derived from the Greek words "trigonon" ("triangle") and "metron" ("to measure"), focused on computing numerical values of triangle parts or shapes disassembled into triangles. Other parts' values were given until the 16th Century. Pythagoras, Aristotle, or the ancient civilization of the Greeks, Egyptians, and Babylonians may come to mind while looking at the dawn of trigonometry.

Pythagoras, the author of the Pythagorean Theorem, was afraid of beans and had a cult to worship triangles, his followers were not only vegan but also didn't eat beans because they believed that a part of their soul escaped every time, they passed gas.

The Pythagorean Theorem, traditionally known as the square of the hypotenuse's length equalling the sum of squares of the other two sides of a right-angled triangle, formulates as a² + b² = c². For example, (3)² + (4)² = (5)².

The Rhind papyrus (1800 BCE) was an Ancient Egyptian Collection of 84 mathematical problems to the likes as Arithmetic, Algebra, and Geometry. The Geometry portion also consisted of five issues dealing with the seked or what we now refer to as the hypotenuse.

The Rhind papyrus' 56th problem addressed a pyramid with a height of 250 cubits and a length of 360 cubits. The solution provided the ratio of 51/25 palms per cubit, equivalent to the pure ratio 18/25 considering that one cubit equals 7 palms.

This referred to the “run-to-rise” ratio of the pyramid in question—in effect, the cotangent of the angle between the base and face, from this we can examine the Egyptians' extent of knowledge of the numerical relations in a triangle along with trigonometry.

The Greeks initiated modern trigonometry, and Hipparchus (120 BCE) formulated the table of values for trigonometric functions. Being an astronomer, he focused on spherical triangles formed by three stars on the celestial sphere. Still, he was also familiar with the basic formulas of plane trigonometry.

The symbols for trigonometry were formulated only in the 17th Century. Ptolemy’s Almagest was the first major ancient work on trigonometry to reach Europe that uses some elementary trigonometry that led to Ptolemy’s geocentric system being a succession of the heliocentric system of Nicolaus Copernicus.

The Babylonians used the Pythagorean Theorem some 1,000 years before Pythagoras was born. They wrote it down on a tablet now known as Plimpton 322.

The ancient Egyptians, Chinese, and Indians all used versions of its centuries before Pythagoras. An ancient Babylonian tablet used the Pythagorean Theorem 1200 years before Pythagoras was born.

India and the Islamic world were also great contributors to trigonometry which makes you wonder about the true importance and value of Mathematics as recent research shows us that 4000 years ago Neanderthals also had a basic sense of Mathematics.