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The value of pi (π) is wrong in the sense that it's an unnatural choice for a circle constant. The circle constant used by Archimedes, π is defined as the circumference of a circle divided by the diameter (C/D = 3.1415...), so there are 2π radians per circle. So it's really the "semicircle constant", not the circle constant. He probably chose to divide by diameter because it's easier to measure, but circles are mathematically defined by their radius, not their diameter.

A more natural circle constant is the circumference divided by the radius (C/r = 6.283185...). This was the value used by Al-Kashi, and is called tau (τ) by people who want to promote it as the circle constant to be taught in schools and used in calculations. There are τ (=2π) radians per circle.

(In fact, the first use of the symbol π was by David Gregory in 1697 to represent a constant of circumference / radius, like τ. However, it was written as a fraction π∕ρ. π originally just meant "circumference"!)

Tau is a better choice because it makes distance around the circle intuitive. 1/4 of the way around a circle is τ/4 radians. 7/8 of the way around is 7τ/8 radians, etc.

It also makes it more obvious that the area of a circle is the result of an integral. For instance, the area of a polygon is 1/2 ⋅ perimeter ∙ apothem. If you increase the number of sides to infinity, it becomes a circle, with an area of 1/2⋅τr⋅r = 1/2⋅τr².

Read the related links for more examples of why τ makes more sense as the circle constant.

Q: Is the value of Pi wrong?

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If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.

The value of pi (Ï€) is3.1415926535897932384626433832795028841971693993751.........

No one has fully discovered pi. Pi is believed to be irrational.

Not sure what the 227 is for but the value of pi is 3.14159265

the value of pi is 3.14159265358979323846264338327950288........ it goes on and on

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If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.If you use the wrong value for pi, you will get wrong, and possibly contradictory, results.

It looks like the decimal value of Pi - however, some of the digits are wrong... 3.14159265358979

Pi times pi equals 9.869604401089358 (to 15 decimal places).The square value 9.8696 is commonly used.If you use (pi)2 = 10 in your calculations, your answer is only wrong by about 1.3% .

The value of Pi is 3.14 so the value of Pi by 2 is 6.28.

The ancientsgave pia value of 3 which is wrong but even today we do not know its exact value only that it is the circumference of a circle divided by its diameter

The value of pi (Ï€) is3.1415926535897932384626433832795028841971693993751.........

The approximate value of pi is 3.14159265.

The value for Pi for math is 3.14. Pi is the 16th letter in the Greek alphabet.

You get the value of pi by dividing the circumference with the diameter of a circle. pi = c/d

No one has fully discovered pi. Pi is believed to be irrational.

Not sure what the 227 is for but the value of pi is 3.14159265

Value for pi in Egypt is 25/8 or √10.