Euclid was a Greek mathematician, who is often referred to as the father often geometry. He compiled, systematically arranged, and wrote portions of the mathematics textbook Elements. Very little is known about Euclid's life. The place and date of birth of Euclid are uncertain, though it is known that he taught mathematics at the museum. Euclid probably studied in Athens and came to Alexandria shortly after 300 b.c. at the invitation of the Egyptian ruler Ptolemy I. Euclid began accepting mathematical truths called axioms and postulates. From them he logically demonstrated 467 propositions of plane and solid geometry. Euclid's book Elements has had a greater influence on scientific thinking than any other work. It included the parallel postulates and the Pythagorean theorem.

Euclid wrote on most branches of mathematics that were known in his time. But only a few oh his other writings have survived. They include works on conic sections, perspective, and pitfalls pit falls in geometry.

Many important axioms or postulates and theorems in geometry deal with facts about congruent figures. Postulates are statements that are assumed to be true and are therefore accepted without proof. Some ofEuclidean h types of postulates, addition postulate, substitution postulate, multiplication postulate, division postulate, parallel postulate and partition postulate. The addition postulate states if a=b and c=d then a+c = b+d. The substitution postulate states a quantity may be substituted for its equal. Multiplication postulate states if a=b and c=d then ac-bd. The division postulate states if a=b and c=d then a/c = b/d. The final postulate is the partition postulate. This states that a whole is equal to the sum of it's parts.

The parallel postulate is important because it tells many angles in an equation. The parallel postulate can form and give many angles. It also states if the line is parallel then the two must have the same slope. Euclidean contributed a lot to our society and made geometry what it is today