Determination of $\pi$
26154
Motivation for Ramanujan's mysterious $\pi$ formula
118374
Is there a proof that $\pi$ is an irrational number?
143093
Determining k: $\int_{6}^{16} \frac{dx}{\sqrt{x^3 + 7x^2 + 8x - 16}} = \frac{\pi}{k}$
126199
Proof of $\pi$ not being a quadratic irrational number.
153664
When is $\Bbb{Z[\zeta_n]}$ a PID?
15477
Nice proofs of $\zeta(4) = \frac{\pi^4}{90}$?
14447
Direct proof that $\pi$ is not constructible
142835
Proving :$\arctan(1)+\arctan(2)+ \arctan(3)=\pi$
134633
How to sum this series for $\pi/2$ directly?
13592
How can $\pi$ be irrational if it can be calculated using an infinite series of rational numbers?
9658
What is the length of a sine wave from $0$ to $2\pi$?
83262
Why is there a factor of $4\pi$ in certain force equations?
130686
How is $3\pi-10$ element of $[-\pi/2,\pi/2]$?
154900
Why is $\pi$ = 3.14... instead of 6.28...?
29517
How to find continued fraction of pi
157066
Do We Need the Digits of $\pi$?
66872
Exact values of $\cos(2\pi/7)$ and $\sin(2\pi/7)$