1. Is It Irrational?
https://www.mathsisfun.com/numbers/irrational-finding.html
2. This video will show you a real-life application of square root of two
3. ISO Paper Sizes
http://www.cl.cam.ac.uk/~mgk25/iso-paper.html
http://www.jkpaper.com/index.php?option=com_content&view=article&id=53&Itemid=54