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Geometry History Home

 

 

Welcome to the new improved GeomHistory.com web site.

This site presents a brief outline of the history of geometry (Ancient, Greek, Medieval, and Modern), with timelines of the major geometers responsible for it's evolution. Click on any person's name or picture for an expanded biography at the History of Mathematics Archive (Univ of St Andrews, Scotland). For the history of geometry, going through our site facilitates accessing the information in the St Andrews Archive.

 
Ancient Geometry (3000 BC - 500 BC)


Babylon (2000 BC - 500 BC)

Babylon_MapThe Babylonians replaced the older (4000 BC - 2000 BC) Sumerian civilization around 2000 BC. The Sumerians had already developed writing (cuniform on clay tablets) and arithmetic (using a base 60 number system). The Babylonians adopted both of these. But, Babylonian math went beyond arithmetic, and devloped basic ideas in number theory, algebra, and geometry. The problems they wanted to solve usually involved construction and land estimation, such as areas and volumes of rectangular objects. Some of their methods were rules that solved specialized quadratic, and even some cubic, equations. But, they didn’t have algebraic notation, and there is no indication that they had logical proofs for the correctness of their rule-based methods. Nevertheless, they knew some special cases of the "Pythagorean Theorem" more than 1000 years before the Greeks (see: Pythagorean Knowledge In  Ancient Babylonia and Pythagorus’ theorem in Babylonian mathematics). Their durable clay tablets have preserved some of their knowledge (better than the fragile Eygptian papyri). Four specific tablets (all from the period 1900 BC - 1600 BC) give a good indication of Babylonian mathematical knowledge:

Plimpton_322Yale tablet YBC 7289 - shows how to compute the diagonal of a square.

Plimpton 322 - has a table with a list of Pythagorean integer triples.

Susa tablet  - shows how to find the radius of the circle through the three vertices of an isoceles triangle.

Tell Dhibayi tablet - shows how to find the sides of a rectangle with a given area and diagonal.

There is no direct evidence that the Greeks had access to this knowledge. But, some Babylonian mathematics was known to the Eygptians; and probably through them, passed on to the Greeks (Thales and Pythagorus were known to have traveled to Egypt).


Egypt (3000 BC - 500 BC)

Rhind_papyrusThe geometry of Egypt was mostly experimentally derived rules used by the engineers of those civilizations. They developed these rules to estimate and divide land areas, and estimate volumes of objects. Some of this was to estimate taxes for landowners. They also used these rules for construction of buildings, most notably the pyramids. They had methods (using ropes to measure lengths) to compute areas and volumes for various types of objects, various triangles, quadrilaterals, circles, and truncated pyramids. Some of their rule-based methods were correct, but others gave approximations. However, there is no evidence that the Egyptians logically deduced geometric facts and methods from basic principles. And there is no evidence that they knew a form of the "Pythagorean Theorem", though it is likely that they had some methods for constructing right angles.  Nevertheless, they inspired early Greek geometers like Thales and Pythagorus. Perhaps they knew more than has been recorded, since most ancient Eygptian knowledge and documents have been lost. The only surviving documents are the Rhind and Moscow papyri.

    Ahmes (1680-1620 BC)
    wrote the Rhind Papyrus (aka the “Ahmes Papyrus”). In it, he claims to be the scribe and annotator of an earlier document from about 1850 BC. It contains rules for division, and has 87 problems including the solution of equations, progressions, areas of geometric regions, volumes of granaries, etc.

    Anon (1750 BC)
    The scribe who wrote the Moscow Papyrus did not record his name. This papyrus has 25 problems with solutions, some of which are geometric. One, problem 14, describes how to calculate the volume of a truncated pyramid (a frustrum), using a numerical method equivalent to the modern formula: Eqn_Vol_Egypt_pyramid, where a and b are the sides of the base and top squares, and h is the height.

The book Mathematics in the Time of the Pharaohs gives a more detailed analysis of Egyptian mathematics.

 
India (1500 BC - 200 BC)

Everything that we know about ancient Indian (Vedic) mathematics is contained in:

The Sulbasutras
Sulbasutras_Pythagorian_TheoremThese are appendices to the Vedas, and give rules for constructing sacrificial altars. To please the gods, an altar's measurements had to conform to very precise formula, and mathematical accuracy was very important. It is not historically clear whether this mathematics was developed by the Indian Vedic culture, or whether it was borrowed from the Babylonians. Like the Babylonians, results in the Sulbasutras are stated in terms of ropes; and "sutra" eventually came to mean a rope for measuring an altar. Ultimately, the Sulbasutras are simply construction manuals for some basic geometric shapes. It is noteworthy, though, that all the Sulbasutras contain a method to square the circle (one of the infamous Greek problems) as well as the converse problem of finding a circle equal in area to a given square. The main Sulbasutras, named after their authors, are:

Baudhayana (800 BC)
Baudhayana was the author of the earliest known Sulbasutra. Although he was a priest interested in constructing altars, and not a mathematician, his Sulbasutra contains geometric constructions for solving linear and quadratic equations, plus approximations of pi (to construct circles) and sqrt-2.  It also gives, often approximate, geometric area-preserving  transformations from one geometric shape to another. These include  transforming a square into a rectangle, an isosceles trapezium, an isosceles triangle, a rhombus, and a circle, and finally transforming a circle into a square. Further, he gives the special case of the “Pythagorean theorem” for the diagonal of a square, and also a method to derive “Pythagorian triples”. But he also has a construction (for a square with the same area as a rectangle) that implies knowing the more general “Pythagorian theorem”. Some historians consider the Baudhayana as the discovery of the “Pythagorian theorem”.  However, the Baudhayana descriptions are all empirical methods, with no proofs, and were likely predated by the Babylonians.
Manava (750-690 BC)
contains approximate constructions of circles from rectangles, and squares from circles, which give an approximation of  pi = 25/8 = 3.125.
Apastamba (600-540 BC)
considers the problems of squaring the circle, and of dividing a segment into 7 equal parts. It also gives an accurate approximation of sqrt-2 = 577 / 408 = 1.414215686, correct to 5 decimal places.
Katyayana (200-140 BC)
states the general case of the Pythagorean theorem for the diagonal of any rectangle.
 

 

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