The Elements of Euclid, Bøker 1-6;Bok 11

ABCD AC is equal angle ABC angle ACB angle BAC Axiom base bisected Book centre circle circle ABC circumference common Construction contained Corollary Definition demonstration described diameter divided double draw drawn edition Elements equal equal angles equiangular equilateral equimultiples Euclid exterior angle extremities fall figure four fourth given given straight line greater half Hypothesis impossible join less Let ABC magnitudes manner meet multiple namely parallel parallelogram pass perpendicular plane polygon PROBLEM produced proportionals Q.E.D. PROPOSITION ratio reason rectangle rectangle contained rectilineal figure right angles segment shewn sides similar Simson square square on AC straight line &c suppose Take taken THEOREM third triangle ABC Wherefore whole