value of "pie" is "22 / 7" or "3.14". why?

Answer 1

By definition, pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter which circle you use to compute it.

this is not 22/7 or 3.14 these are approximate values

Answer 2

The value of "pie" cannot be expressed exactly, either as a fraction or as a decimal.

355/113 is a better approximation than either 22/7 or 3.14.

There are dozens of numbers in mathematics which just turn out to be whatever value they happen to have. Gamma, Euler's Constant, e, phi, . . . the list never ends, and they are what they are, without any "why?".

Answer 3

"Pie" is a round, baked dessert.

"Pi" is a number.

22/7 and 3.14 are ONLY approximations of pi. The real number has an endless string of digits can can't be expressed as a fraction nor a terminating decimal.

As for "why" it is the value it is, well pi by definition is the ratio of a circle's circumference to it's diameter. That allways happens to be the same exact value: 3.14159265358979...

Answer 4

∏= 3.1415926535897932384626433832795

22/7= 3.1428571428571428571428571428571

so pi is not eq. to 22/7--- it is the ratio of circumference of a circle to it's diameter.

22/7 is an approx. value of pi correct to 2 decimals and is so often used in basic problems at school.

Answer 5

Pi is approximately equal to 3.141592654, but it is a non-terminating number which means it goes forever. It is the ratio in any circle of Circumference divided by diameter. It is one of the great mysteryie of life why pie is a non-terminating number (has an infinite number of decimal places).

Answer 6

The value of π has been known in some form since antiquity. As early as the 19th century BC, Babylonian mathematicians were using π = 25⁄8, which is within 0.5% of the true value.

The Egyptian scribe Ahmes wrote the oldest known text to give an approximate value for π, citing a Middle Kingdom papyrus, corresponding to a value of 256 divided by 81 or 3.160.

It is sometimes claimed that the Bible states that π = 3, based on a passage in 1 Kings 7:23 giving measurements for a round basin as having a 10 cubit diameter and a 30 cubit circumference. The discrepancy has been explained in various ways by different exegetes. Rabbi Nehemiah explained it by the diameter being measured from outside rim to outside rim while the circumference was the inner brim; but it may suffice that the measurements are given in round numbers.


Principle of Archimedes' method to approximate πArchimedes of Syracuse discovered, by considering the perimeters of 96-sided polygons inscribing a circle and inscribed by it, that π is between 223⁄71 and 22⁄7. The average of these two values is roughly 3.1419.

The Chinese mathematician Liu Hui computed π to 3.141014 in AD 263 and suggested that 3.14 was a good approximation.

The Indian mathematician and astronomer Aryabhata in the 5th century gave the approximation π = 62832⁄20000 = 3.1416, correct when rounded off to four decimal places. He also acknowledged the fact that this was an approximation, which is quite advanced for the time period.

The Chinese mathematician and astronomer Zu Chongzhi computed π to be between 3.1415926 and 3.1415927 and gave two approximations of π, 355⁄113 and 22⁄7, in the 5th century.

The Indian mathematician and astronomer Madhava of Sangamagrama in the 14th century computed the value of π after transforming the power series of arctan(1)=π⁄4 into the form


and using the first 21 terms of this series to compute a rational approximation of π correct to 11 decimal places as 3.14159265359. By adding a remainder term to the original power series of π⁄4, he was able to compute π to an accuracy of 13 decimal places.

The Persian astronomer Ghyath ad-din Jamshid Kashani (1350–1439) correctly computed π to 9 digits in the base of 60, which is equivalent to 16 decimal digits as:

2π = 6.2831853071795865
By 1610, the German mathematician Ludolph van Ceulen had finished computing the first 35 decimal places of π. It is said that he was so proud of this accomplishment that he had them inscribed on his tombstone.

In 1789, the Slovene mathematician Jurij Vega improved John Machin's formula from 1706 and calculated the first 140 decimal places for π, of which the first 126 were correct [1], and held the world record for 52 years until 1841, when William Rutherford calculated 208 decimal places of which the first 152 were correct.

The English amateur mathematician William Shanks, a man of independent means, spent over 20 years calculating π to 707 decimal places (accomplished in 1873). In 1944, D. F. Ferguson found that Shanks had made a mistake in the 528th decimal place, and that all succeeding digits were incorrect. By 1947, Ferguson had recalculated pi to 808 decimal places (with the aid of a mechanical desk calculator).


Numerical approximations
Main article: History of numerical approximations of π
Due to the transcendental nature of π, there are no closed form expressions for the number in terms of algebraic numbers and functions. Formulæ for calculating π using elementary arithmetic invariably include notation such as "...", which indicates that the formula is really a formula for an infinite sequence of approximations to π. The more terms included in a calculation, the closer to π the result will get, but none of the results will be π exactly.

Consequently, numerical calculations must use approximations of π. For many purposes, 3.14 or 22/7 is close enough, although engineers often use 3.1416 (5 significant figures) or 3.14159 (6 significant figures) for more precision. The approximations 22/7 and 355/113, with 3 and 7 significant figures respectively, are obtained from the simple continued fraction expansion of π. The approximation 355⁄113 (3.1415929…) is the best one that may be expressed with a three-digit or four-digit numerator and denominator.

The earliest numerical approximation of π is almost certainly the value 3. In cases where little precision is required, it may be an acceptable substitute. That 3 is an underestimate follows from the fact that it is the ratio of the perimeter of an inscribed regular hexagon to the diameter of the circle.

Answer 7

Pi is the ratio between the circumference of the circle and the diameter. Take any circile and the ratio between the two will always equal pi.

Answer 8

Report me if you like for being a *****, I officially don't care but Nateena is a bloody liar. 4% of her answers are best answers. Never been given a best answer? Take a long walk off a short cliff you lying rat. But that was a fairly good joke. Didn't make me laugh but it was original.

Answer 9

I have always used the 3.141592654 value, that is what they taught me in school and it always worked. Not sure of the 22/7. That may be for more advanced formulas.

Answer 10

22/7 is exact & 3.14 is an approximation as 22/7 is a non repeating non terminating decimal.