Keywords: Byrne 1847 Pythagoras Querformat.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_Satz_des_Pythagoras_Hochformat jpg Oliver Byrne mathematician Euclid Pythagorean theorem Euclid's proof of Pythagorean theorem |