Book I. Rectilinear Figures 48

Book II. Geometric algebra 14 Book III. Circles 37 Book IV. Problems about circles 16 Book V. Proportion 25 Book VI. Applications of proportion 33 ---- 173

Of these we now omit Euclid's Book II, because we have an algebraic symbolism that was unknown in his time, although he would not have used it in geometry even had it been known. Thus his first proposition in