Book I. ΔΔ Δ A XXVI. XXVII. XXVIII. XXIX. XXX. equal, and all its angles right angles. XXXI. XXXII. not right angles. XXXIII. another, but all its sides are not equal, nor its angles right XXXIV. Book I. XXXV. which being produced ever so far both ways, do not meet. POSTULATES. I. LET it be granted that a straight line may be drawn from any one point to any other point. II. III. distance from that centre. AXIOMS. I. II. III. IV. V. VI. VII. VIII. exactly fill the same space, are equal to one another. Book I. IX. X. XI. XII. “ two interior angles on the same side of it taken together “ less than two right angles, these straight lines being con“ tinually produced, shall at length meet upon that side on “ which are the angles which are less than two right angles. “ See the notes on prop. 29. of book I." a |