1 1 2 3 5 8 13 21 34 55 89 144 .........[br][br] a b a/b[br] 1  2 0.5[br] 2  3 0.67[br] 3  5 0.6[br] 5  8 0.63[br] 8 13 0.62[br]13 21 0.62[br]21 34 0.62[br][br][size=150][color=#ff00ff] "phi"=[/color][math]\phi[/math][color=#ff00ff] =sezione aurea? come si trova?[/color][/size]