# Tagged Questions

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### Chinese estimate for $\pi$. Were they lucky?

The famous chinese estimate $\pi\approx\frac{355}{113}$ is good. I think that is too good. As a continued fraction: $$\pi=[3:7,15,1,292,\ldots]$$ That $292$ is a bit too big. Is there a reason for a ...
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### Not pi - What if I used 3? Teaching pi discovery to K-6th grade

So, in ancient Mesopotamia they knew that they didn't really have the correct number (pi) to determine attributes of a circle. They rounded to 3. If you acted as though pi = 3, what shape would you ...
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### Proofs without words of some well-known historical values of $\pi$?

Two of the earliest known documented approximations of the value of $\pi$ are $\pi_B=\frac{25}{8}=3.125$ and $\pi_E=\left(\frac{16}{9}\right)^2$, from Babylonian and Egyptian sources respectively. ...
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### How exactly do you measure circumference or diameter?

I am absolutely confused about trying to calculate circumference. And I do not mean using the math formula, I mean back in old days when people had very primitive tools, and had to make the ...
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### Did Euclid prove that Pi is Constant?

Pi is defined the ratio of the circumference of a circle to its diameter, but of course different circles have different circumferences and diameters, so in order for it to be well-defined we need to ...
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### How to calculate π [duplicate]

Possible Duplicate: Simple numerical methods for calculating the digits of Pi How do people/computers calculate π? Im sure long ago, someone just took a measurement of the circumference of ...
### When was $\pi$ first suggested to be irrational?
When was $\pi$ first suggested to be irrational? According to Wikipedia, this was proved in the 18th century. Who first claimed / suggested (but not necessarily proved) that $\pi$ is irrational? I ...
### Approximation for $\pi$
I just stumbled upon $$\pi \approx \sqrt{ \frac{9}{5} } + \frac{9}{5} = 3.141640786$$ which is $\delta = 0.0000481330$ different from $\pi$. Although this is a rather crude approximation I ...