Keywords: Byrne 1847 Satz des Pythagoras Hochformat.jpg en Oliver Byrne illustrated the work of Euclid Oliver Byrne 1847 The First Six Books of The Elements of Euclid Dr Mirko Junge 1847 PD-old-100 Byrne_1847_Pythagoras_Querformat jpg Oliver Byrne mathematician Euclid Pythagorean theorem Euclid's proof of Pythagorean theorem |