The Thirteen Books of Euclib's Elements.

added addition alternative Apollonius appears applied Aristotle assumed attributed axiom base Book called centre circle commentary common construction contained corresponding definition demonstration described direction distance draw drawn edition Elements enunciation equal Eucl Euclid existence explain expression extremities fact figure follows geometry given gives greater Greek hand Heiberg Heron hypothesis included joined later lemma length less magnitude means meet mentioned method namely necessary notion objection observes opposite original Pappus parallel parallelogram particular passage perpendicular plane position possible postulate principles problem Proclus produced proof proposition proved quoted rectangle reference regards remaining remarks respectively right angles says scholia seems segment sense sides similar solid square straight line suppose surface taken term theorem things translation triangle true whole