Square Roots Using a Carpenter's Square
As demonstrated in a PUMAS example from Lin H Chambers, "How Now, Pythagoras", master carpenters regularly make practical use of geometry and, at times, the Pythagorean theorem in their craft. I found this out some time ago when a good friend told me how an old-time carpenter he worked with calculated square roots using a carpenter's square. This carpenter performed his craft long before calculators arrived on the scene and, I'm sure, applied this method to numerous applications where he needed to ensure square corners or needed the length of a diagonal prior to cutting materials for construction. Being a mechanical engineering student at the time I learned this method, I was impressed by the elegant simplicity of it. I'm still impressed.