If a straight line be bisected and a straight line be added to it in a straight line, the rectangle contained by the whole with the added straight line and the added straight line together with the square on the half is equal to the square on the straight line made up of the half and the added straight line.
Si recta linea dividatur in duo equalia, apponatur autem quedam ipsi recta in directo, sub tota cum adiacente et adiacente contentum orthogonium cum eo quod a dimidia tetragono equale est ei quod a composita ex dimidia et adiacente ut ab una descripto tetragono.
Si linea recta in duas dividatur medietates et recta linea in ipsius rectitudine ei addatur, superficiesrectorum angulorum que continetur a tota prima linea et addita et addita cum quadrato facto ex medietate prime linee quadrato facto ex linea composita ex medietate prime et addita equalis erit.
اذا قسم خط مستقيم بنصفين وزيد فى طوله خط اخر مستقيم فان السطح الذى يحيط به الخط كله مع الزيادة والزيادة ومربع ٣٠ نصف الخط الاول مساو لمربع نصف الخط مع الزيادة
SI recta linea bifariam secetur, & illi recta quædam linea in rectum adiiciatur: Rectangulum comprehensum sub tota cum adiecta, & adiecta, vna cum quadrato a dimidia, æquale est quadrato a linea, quæ tum ex dimidia, tum ex adiecta componitur, tanquam ab vna, descripto.
Title
Book I
