Euclid was the famous mathematician of Greece. He was often referred to as Euclid of Alexandria as there was Euclid of Megara. He is well known as the “Father of Geometry”. He was active in Alexandria during the reign of Ptolemy.

Fact 1Who Was Euclid?
According to some, Euclid was a historical figure whose famous work is the book called “Elements”. The exact date of birth is not known. It is believed that he was born around 325 BC and passed away about 265 BC. He was active during the reign of Ptolemy between 323 BC and 283 BC IN Alexandria and was famous for his “The Elements”- a treatise on Mathematics.

Fact 2 Life Of Euclid
There are no significant details about Euclid of Alexandria’s life. The little information that is available is from what is reported by the Greek philosopher Proclus (c.410 – 485 CE) in his “summary” of mathematicians of Greece. According to him also, Euclid lived during the reign of Ptolemy 1 Soter who ruled over Egypt and that Euclid was a teacher in Alexandria. During the medieval age, translators confused him with Euclid of Megara and it is for this reason he is often referred to as Euclid of Alexandria. There is another proof offered by Proclus that Euclid lived during the period when Ptolemy was the ruler. He wrote that Ptolemy wanted to find a shorter way to geometry and asked Euclid about it and he replied that it was not possible to travel by a royal road to learn Geometry. However there are some historians who are of the opinion that Euclid lived even before Archimedes ( 290/280 BCE to 212/213 BCE).

Fact 3 Controversies About His Book
There are many controversies regarding the book written by Euclid. Some say that Euclid had a team of mathematicians and they all worked together in Alexandria to complete the work he started “The Elements” and even continued to write after his death under his name. Some feel that the treatise was the work of a group of mathematicians of Alexandria who assumed the name of Euclid.

Fact 3 Other Works Of Euclid
Since there is no concrete proof about Euclid, what is known about his other works is from the writings and references of other writers. There is a book titled Data which discusses propositions and plane geometry. In these propositions, certain information is offered regarding a figure and from these other data is figured out. “On Division” is another book that deals with general division problems of plane geometry. A well known work of Euclid that is still available is “Phenomena”. Today this is known as “Applied Mathematics” and is concerned with the geometry of spheres that is used in Astronomy.

Fact 4 The Work “The Optics”
There is another book available of Euclid called The Optics. This treatise explains that the sun and other satellites or heavenly bodies that we see in the sky are not of the size that we perceive them with our naked eyes. This work elucidates the relationship between an object and its visibility. What the eyes see is not always perfect. As an example Euclid has shown that human eyes perceive only half of a circle and nearness to the same sphere that is seen becomes smaller whereas actually it appears to be larger.

Fact 5 Lost Work Of Euclid
Another treatise of Euclid is Prisms. It is more like a theorem as well as a problem Here there is nothing to be proved or constructed which is normal in geometry, rather it is about prisms that brings out another important aspect which is already present there. This is a more advanced work of Euclid but unfortunately it is lost.