I believe that was why the pythagoreans chose the pentagon as their secret symbol?

+,-,/,*, arithmetic, algebra, geometry, Reimann(ian) geometry, trigonometry, exponential, root, log, functions,sigma summation, derivitive calc, integral calc, zymergy, DC electricity, AC and polyphase electricity, steam, periodic table, farming, floatation and boats, sailing and navigation, whoever figured when it was safe to eat oysters!, and that there was something good to eat in an artichoke (your going to try and eat

*that*?), all the healing arts and medicine, most all semiconductor stuff, radio, RADAR, electromagnetic waves, satellites, space telescopes, Lagrange points, ... 'modern coffee apparatus'... the printing press, refraction and reflection of light - optics at large, pencils and erasers, musical instruments and sound (withing some limits for me personally). Periodic table. most things to do with chemestry especially the carbon cycle and the nitrogen cycle. Proof that pi is trancendental... are the same (though we dont know it completely) number when and where pops up (if you want to do the proof my hats off to you!) and all that came of that. Kelvins "On an Absolute Thermometric Scale", Libraries. Anything to do with maths for spacetime that is predictive and somehow testable.

I think all those are prtty interesting off the top on my head.