TITLE: Prove that $\pi$ is a transcendental number
QUESTION [19 upvotes]: Does anyone has a link to a site that confirms that $\pi$ is a transcendental number?
Or, can anyone show how to prove that $\pi$ is a transcendental number?
Thank you in anticipation!

REPLY [17 votes]: As suggested by Yuval's comment, the most straightforward way of showing that $\pi$ is transcendental proceeds through the Lindemann–Weierstrass theorem that $e^x$ is transcendental if $x$ is (nonzero and) algebraic; since $e^{i\pi}=-1$ is algebraic, then $i\pi$ must be transcendental, and therefore $\pi$ must be (since $i$ isn't rational, but it is algebraic!).  You can find a rough proof of the theorem at its Wikipedia page.

REPLY [10 votes]: Try the short paper The transcendence of $\pi$ by Niven 
and his book Irrational Numbers.