Euclid's Elements Reference Page

• Book I
  Basic geometric notions and constructions. The first treatment of the Pythagorean theorem.

• Book II
  Geometric algebra.

• Book III
  Circles, inscribed angles, tangents, power of a point.

• Book IV
  Inscribed and circumscribed triangles and regular pentagon, hexagon, quindecagon

• Book V
  Proportion

• Book VI
  Similar figures. The second treatment of the Pythagorean theorem.

• Book VII
  Basics of Number Theory: primes, divisibility, GCD, LCM.

• Book VIII
  Geometric sequence, proportions.

• Book IX
  More of Number Theory: perfect numbers, sum of geometric series.

• Book X
  Method of exhaustion.

• Book XI
  Basics of the 3D geometry.

• Book XII
  Volumes by the method of exhaustion.

• Book XIII
  Golden section and Platonic solids.

References

1. T. L. Heath, Euclid: The Thirteen Books of The Elements, Dover, 1956
2. R. Simson, The Elements of Euclid, Books I-VI, XI, XII + Euclid's Data, Elibron Classics, 2005