The Golden Ratio: a designer's guide. The Golden Ratio is a beautifully simple piece of mathematical theory that can help make your designs feel well proportioned and pleasing on the eye. We explain how to use it.
The Fibonacci sequence in all of its perfect beauty. via Algeblog 9 (because maths can be fun!)
The Golden Ratio and Golden Triangle used as the 'blueprint' for da Vinci's "Mona Lisa."