how was it found that pi is equal to 22/7 or 3.14?

Question

please let me know soon

Answer 1

Hellenistic (Greek) mathematicians discovered, through much measurement and calculation, that the ratio between the diameter and circumference of a circle was equal to 3.141592654...

Answer 2

Pretty simple. Draw a circle of a given diameter. Then cover the circle with a rope until the end meets the other part of the rope. Cut the rope at that point. Then measure the ratio between the diameter and the rope. PS: pi is approximated by these terms. Since 22/7=3.14296 (to 5 places) and pi=3.14159 (to five places), the 140 parts in 314,000 is quite close, and you would probably not be able to get any closer with your rope.

PPS: The ancient Egyptians first estimated pi as 3. In differential equations, pi is equal to an infinite series, so in theory you can evaluate it. Computers have estimated it to thousands of decimal places, but it still is irrational.

Answer 3

History of Pi
The history of π parallels the development of mathematics as a whole. Some authors divide progress into three periods: the ancient period during which π was studied geometrically, the classical era following the development of calculus in Europe around the 17th century, and the age of digital computers.

That the ratio of the circumference to the diameter of a circle is the same for all circles, and that it is slightly more than 3, was known to ancient Egyptian, Babylonian, Indian and Greek geometers. The earliest known approximations date from around 1900 BC; they are 25/8 (Babylonia) and 256/81 (Egypt), both within 1% of the true value. The Indian text Shatapatha Brahmana gives π as 339/108 ≈ 3.139. The Books of Kings (600 BC) appears to suggest π = 3, which is notably worse than other estimates available at the time, although the interpretation of the passage is disputed.

Answer 4

"Pi or π is one of the most important mathematical constants, approximately equal to 3.14159. It represents the ratio of any circle's circumference to its diameter in Euclidean geometry, which is the same as the ratio of a circle's area to the square of its radius. Many other formulas from mathematics, science, and engineering include π. It is an irrational number, which means that its decimal expansion never ends or repeats."

Answer 5

this is more of an activity.take a compass and draw a circle with any radius.write down its radius.take a thread and find its circumference by putting the thread on the borders of the circle u just created.now that u have got the circumference divide it by the radius and u will get the value as 22/7.
Circumference/radius is always constant (i.e. 22/7) which we call pi.
try with different radii and you will get it
If you have more problems tell me

Answer 6

I think I might be able to find the answer with a ruler, but π was first estimated as 3 by (I THINK) Euclid. I don't study history so go knock yourself out with wikipedia.
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EDIT: Someone must have brainwashed me. Now I remember! Archimedes first estimated π!
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EDIT: Actually I just looked at the above answerers.

Answer 7

if you had a circle and it was 1 in diameter and rolled it , it would take 22/7 to roll back to the point

Answer 8

Here's how Archimedes did it (interactive video) - inscribing polygons in and around circles - http://www.pbs.org/wgbh/nova/archimedes/pi.html

Answer 9

http://en.wikipedia.org/wiki/Pi#Geometrical_period