Am now on page 214 after an edit. Have added a really simple convergence proof for the Fibonacci ratio converging on Phi – so simple that it could even be Pythagorean. Also added an exact and not a fudged analysis of DaVinci’s Vitruvian man with no relation to Phi, just Vitruvius. This is all in the Perspective chapter – an odd place you might think – but it follows nicely after Egyptian grids on the way to perspective drawings, Futurism, Cubism, etc.