Thread: value of pi

why value of pi is 22/7

History of Pi

check this link: History of Pi

Originally Posted by Kit

why value of pi is 22/7

-dividing circumference of any circle to its diameter gives a constant value pi

The value of pi isn't necessarily 22/7 that's just a fractional expression that is relatively close and doesn't repeat just like pi.

22/7 = 3.14285714
pi = 3.14159265

that was just taken from google's calculator, if you want a full explanation, I would personally suggest wikipedia, they will more than likely have the actual formula for finding pi.

Hope I was of some help

Pi is an irrational number meaning that it not the ratio of any two integers.
It is defined as the ratio of the circumference(C) of a circle to its diameter(D).

C = pi*D

Thus pi = C/D

eregouf@gmail.com
Exciting Science and Disasters

It's not really 22/7, that is a rational approximation. I think that it is the mathematician's need for numbers to be rational.

The real question is why would the ratio of the circumference of a circle to its diameter be irrational and not exact. Why couldn't the circumference of a circle be 1/3 of its diameter?

Originally Posted by leetownreb

It's not really 22/7, that is a rational approximation. I think that it is the mathematician's need for numbers to be rational.

no, using 22/7 just makes pi calculations easier, if you aren't using a calculator.

Any rational number (integer/integer) will eventally repeat. Taking 22/7 into long division will after each step result in a remainder between 0 and 6 and so will repeat after at most 7 digits.
3.142857142857 142857 142857 142857

This is off by only .04% so it's a pretty good estimate.

One method to find Pi is to consider the perimeter of a regular n-sided polygon, and take the limit as n approaches infinity.