Explanation

Euclid, also known as  Euclid of Alexandria , was a Greek mathematician, often referred to as the "founder of geometry" or the "father of geometry".

Explanation

On September 14, 1939, the VS-300, the world's first practical helicopter, took flight at Stratford, Connecticut.

Explanation

Vasco Da Gama was the first European to reach India by sea.

Vasco Da Gama was a famous Explorer

Vasco Da Gama belonged to Portugal

Vasco da Gama was born in 1460 in the town of Sines

Explanation

British scientist Joseph Priestly discovered oxygen on August 1, 1774.

Explanation

• The study of angles and of the angular relationships of planar and three-dimensional figures is known as trigonometry.

• Hipparchus was a Greek astronomer who lived between 190-120 B.C.

• Hipparchus is considered the father of trigonometry.

Explanation

Ibn Khaldun was: sociologist and historian

Ibn Khaldun born: Tunis 

Ibn Khaldun died: Egypt

Explanation

Founded February 4, 2004

Headquarters: Menlo Park, California, U.S.

 Facebook was founded by Mark Zuckerberg, along with his fellow roommates