Euclid structured each book into four groups.
Book I - VI -- Plane geometry Books one and two lay down the basic properties of triangles, parallels, parallelograms, rectangles, and squares. Book three deal with the properties of the circle. Book four dealt with the problems of circle and is thought to set out work of the followers of Pythagoras. The work of Eudoxus is laid out on proportion applied to commensurable and incommensurable magnitudes in book five, while book six look at applications of the results of book five to plane geometry.
Book VII - IX -- Theory of Numbers Books seven to nine dealt with theory of numbers. Book seven is a self-contained introduction to number theory. It contains the Euclidean algorithm for finding the greatest common divisor of two numbers. Book eight looked at numbers in geometrical progression.
Book X -- Incommensurables Book ten covered mainly the work of Theaetetus and dealt with the theory of irrational numbers. Euclid altered the proofs of several theorems in this book so that they fitted the new definition of proportion given by …show more content…
During the period Euclid was highly respected as a mathematician and Elements was considered one of the greatest mathematical works of all time. The publication was used in schools up to 1903.
In his time, Euclid was attacked by many of his colleagues for being too detailed and including self-evident data, such as one side of a triangle can not be longer than the sum of the other two sides. Today, most mathematicians attack Euclid for the exact opposite reason. They feel he was not thorough enough. In Elements, there are missing areas which were forced to be filled in by following mathematicians. In addition, several errors and questionable ideas have been found.
Euclid also wrote other books, some of which have survived through the time and some of which have not. A few that have survived are: Data, which was a companion volume to the first six books of The Elements, written for beginners. It looks at what properties of figures can be deduced when other properties are given. It includes geometric methods for the solution of quadratics; Division of Figures, a collection of thirty-six propositions relating to the division of plane configurations. It survived only in Arabic translations; Phaenomena, on spherical geometry, which is similar to the work by Autolycus; and Optics, an early work on perspective including optics, catoptrics and