This short paper deals with a derivation of the three-dimensional Pythagorean Theorem employing the general equation of a circle. However, I am not presenting this paper with any kind of proofs or explanations for the concepts assisting the derivation of the Pythagorean Theorem.
This is the example provided in the user guide for the dinbrief package. This package implements a document layout for writing letters according to the rules of DIN (Deutsches Institut für Normung, German standardisation institute).
Edit: This example now allows you to render umlauts with the typical \"a \"o \"u \ss commands if you're not working using a German keyboards (in addition to allowing ä ö ü and ß directly) - our thanks to Danny Werb for his help in setting this up.
This example shows how to set the options for automatic syntax highlighting for code in LaTeX with the listings package (which provides the lstlisting environment). The listings package supports many languages, including Java, C, C++, MATLAB/Octave and Python, and you can set the language option globally with \lstset or for each listing, when you have listings in multiple languages.