Trigonometry is the study of the relations between the sides and angles of triangles. The
word “trigonometry” is derived from the Greek words trigono (τρ´ιγωνo), meaning “triangle”,
and metro (µǫτρω´ ), meaning “measure”. Though the ancient Greeks, such as Hipparchus
and Ptolemy, used trigonometry in their study of astronomy between roughly 150 B.C. - A.D.
200, its history is much older. For example, the Egyptian scribe Ahmes recorded some rudimentary
trigonometric calculations (concerning ratios of sides of pyramids) in the famous
Rhind Papyrus sometime around 1650 B.C.
