# Euclid

## Theorems

THE LOGICAL THEORY OF PLANE GEOMETRY consists of first principles followed by propositions, of which there are two kinds: theorems and problems. A proof from Euclid's elements that, given a line segment, an equilateral triangle exists that includes the segment as one of its sides. The proof is by construction: an equilateral triangle ΑΒΓ is made by drawing circles Δ and Ε centered on the points Α and Β, and taking one intersection of the circles as the third vertex of the triangle.

## Mathematics

Euclid sometimes called Euclid of Alexandria to distinguish him from Euclid of Megara, was a Greek mathematician, often referred to as the "Father of Geometry". He was active in Alexandria during the reign of Ptolemy I (323–283 BC). His Elements is one of the most influential works in the history of mathematics, serving as the main textbook for teaching mathematics (especially geometry) from the time of its publication until the late 19th or early 20th century.

## Character Traits

Euclid was the most prominent mathematician of Greco-Roman antiquity, best known for his treatise on geometry, the Elements.

## Characteristics of the Time Period

The Greek mathematician Euclid wrote the Elements, a thirteen-volume set of textbooks of geometry (the study of points, lines, angles, and surfaces)–the oldest major mathematical work existing in the Western world.

## Other’s View on the Mathematician

Euclid gathered up all of the knowledge developed in Greek mathematics at that time and created his great work, a book called 'The Elements' (c300 BCE). This treatise is unequaled in the history of science and could safely lay claim to being the most influential non-religious book of all time. Euclid probably attended Plato's academy in Athens before moving to Alexandria, in Egypt. At this time, the city had a huge library and the ready availability of papyrus made it the center for books, the major reasons why great minds such as Heron of Alexandriaand Euclid based themselves there.