# History of Pie

Topics: Pi, Circle, Geometry Pages: 3 (789 words) Published: May 5, 2013
History
Mathematicians have known about pi for thousands of years because they have been working with circles for the same amount of time. Civilizations as old as the Babylonians have been able to approximate pi to many digits, such as the fraction 25/8 and 256/81. Most historians believe that ancient Egyptians had no concept of π and that the correspondence is a coincidence.[4] The first written reference to it dates to 1900 BC.[5] Around 1650 BC the Egyptian Ahmes gave a value in the Rhind Papyrus. The Babylonians were able to find that the value of pi was slightly greater than 3 by simply making a big circle and then sticking a piece of rope onto the circumference and the diameter, taking note of their distances, and then dividing the circumference by the diameter.[6] Knowledge of the number pi passed back into Europe and into the hands of the Hebrews, who made the number important in a section of the Bible called the Old Testament. After this, the most common way of trying to find pi was to draw a shape of many sides inside any circle and use the area of the shape to find measure pi. The Greek philosopher Archimedes, for example, used a polygon shape that had 96 sides in order to find the value of pi, but the Chinese in 500 A.D. were able to use a polygon with 16,384 sides to find the value of pi. The Greeks, like Anaxagoras of Clazomenae, were also busy with finding out other properties of the circle, such as how to make squares of circles and squaring the number pi. Since then, many people have been trying to find out more and more exact values of pi.[7] A history of pi|

Philosopher| Date| Approximation|
Ptolemy| around 150 A.D.| 3.1416|
al-Khwarizmi| around 800 A.D.| 3.1416|
al-Kashi| around 1430 A.D.| 3.14159265358979|
Viète| 1540–1603| 3.141592654|
Roomen| 1561–1615| 3.14159265358979323|
Van Ceulen| around 1600 A.D.| 3.14159265358979323846264338327950288| In the 16th century,...