What is correct value of pi, ?

Answer 1

pi= the circumference of a circle divided by the diameter

approx 3.14159

Answer 2

Asrul,

There are a lot of really bad (deliberately so?) answers here. Please be careful. I guess people just want their 2 points and don't care what rubbish they write - not really the philosophy of this site.

Pi IS the ratio of the circuference of a circle to its diameter.

It is NOT 22/7 or, indeed, any other fraction.

It is NOT imaginary, or complex.

It is NOT a recurring decimal.

It is an irrational number which means that it cannot be written as a fraction and that its decimal expansion is non-terminating and non-recurring (ie the same block of numbers does NOT repeat itself indefinitely).

In fact, it is in a category of the irrational numbers called the transcendental numbers. This means that it cannot be written as the solution to a polynomial equation with integer coefficients. This is a bit technical but it basically means that pi is NOT the solution of any 'simple' equation. In fact, most numbers are transcendental!

There are plenty of ways of calculating pi. For example, the following series (you should be able to spot the pattern to complete the series):

pi = 4*(1/1 - 1/3 + 1/5 - 1/7 + ....)

pi = 2* (2/1)*(2/3) * (4/3)*(4/5) * (6/5)*(6/7) * (8/7)*(8/9) * ...

pi turns up all over the place in mathematics, not just when considering the area and circumference of circles. It really is one of the very fundamental numbers (the big 5 are 0, 1, i, pi and e)

I hope that this is what you were after.

Answer 3

the correct value of pi? Circumference of a Circle divided by its Diameter. That's the most correct answer, if someone gives you 22/7, that is an approximate answer, if other gives 3.1415...10^100000000 digits later, that's a rounded answer.

Someone (don't know who), has proven that the value of pi is irrational, you can't describe it as x/y, and thus you can't define it's exact value as a number either. Like square root of 2, or Phi, the Golden Ratio. Pi is usually approximated by the value of 22/7 or 3.14, but they're not the exact value, you can be writing every milimeter of the universe with numbers and still won't find the last digit of pi.

Answer 4

I teach this to three year old children in a simple way. The answers, of course, are correct above. But, just for fun:

1. Make a big circle on a page of paper.
2. Mark the centerpoint. Fold the circle in half and then refold another way in half. Open up and you'll see your centerpoint.
3. Use string or cord, about as long as your leg
4. With the string, measure across from one side of the circle to the other side right through the centerpoint. That's the diameter length.
5. Cut the cord so that you have three strings that are as long as the diameter.
6. Now, place those three strings around the outside edge of the circle. The outside edge is called the circumference.
7. It takes all three strings to go around the circumference. But, not quite. There's a little piece missing.
8. The circumference of a circle is always like that. It takes three strings as long as the diameter, plus a little piece, to go all the way around.
9. "Pi" is the Greek letter we use for that number, three and a little piece.
10. The number for Pi is 3.14159265
11. Pi means, it takes three diameters, plus a little piece to equal the circumference.
12. Pi is a mysterious number because it never ends. The actual measurement of that little piece goes on forever, as far as we know so far.
13. Here is a website about the number Pi . Computers are taking Pi to about 2 billion places I believe.

http://www.angio.net/pi/piquery

Answer 5

The 'correct' value can't be written down because it's full expression goes on forever.

22/7 is a good approximation

355/113 is an even better approximation

3.14159 is the best decimal expression to 6 significant digits.

If you write Pi to 50 decimal places the value is so accurate that the error in circumference of any circle which will fit within the size of the known universe is less than the diameter of a proton.

It has been evaluated to over one trillion decimal places.

Answer 6

no computer can give the exact value of Pi with all its decimals but how's this for a start
3,141 592 653 589 793 238 462 643 383 279 502 884 197 169 399 375 105 820 974 944 592 307 816 406 286 208 998 628 034 825 342 117 067 .................................

Answer 7

yesterday coincidentally I read that the Japanese once calculated the valued of pi to 1.24 trillion decimal places. The people answering 22/7 are not giving you the value of pi but the closest fractional approximation. A typical calculator will give 3.14159265 but of course the value ( decimal places ) continues indefinitely. For a question on a test or assignment the calculator value is sufficient to get the answer.Philosophically pi has no determined conclusion and apparently no pattern of repetition.

Answer 8

The correct value of pi is never ending by you can get as close as...

3.1415926535897932384626433832795

You can reduce as much as 3.14 (You'll use this on test a lot if you can't have a calculator...

3.1416 is a more specific answer...

355 / 113 is also a fraction that you can use...

pi is for finding the area or circumference of a circle...

Area = (pi)r²
Circumference = 2(pi)r

Answer 9

no computer can give the exact value of Pi with all its decimals but how's this for a start
3,141 592 653 589 793 238 462 643 383 279 502 884 197 169 399 375 105 820 974 944 592 307 816 406 286 208 998 628 034 825 342 117 067 .....................................

Answer 10

You cannot give a correct value. Pi has an unlimited number of decimal places.

Answer 11

The correct value of pi is pi. If you start to write it down numerically then you are approximating, no matter how many decimals you go to.