By: Cindy Szeflinski and Ashley Mahoney "It is time that you learned your history..." By: Cindy Szeflinski and Ashley Mahoney

Somewhere Over the Rainbow Triangle angles are found through right triangle trigonometry...but where did trigonometry originate from?

Greek Trigonometry Trigonometry originated in ancient Greece through the studies of Hipparchus of Bithynia (190-120 B.C.) His research lead him to the use of trigonometric ratios to enable the calculation of a certain planet’s position. Angles were depicted through the Babylonian measure of 360 degrees. In addition, cosine and sine resulting sin2 x + cos2 x = 1.

Medieval Trigonometry Tangent was introduced by the Chinese. Through the use of the Greek half-angle formula the Indians produced their own sine and cosine tables. In addition, techniques of approximation to a relatively high accuracy were brought to the surface. Indian works were translated and read by the Islamic mathematicians. The Indian sine was used, as well as the chord. Cosine formally introduced, by Abu Abdallah Muhammad ibn Jabir al-Battani. Cotangent, cosecant and secant functions were introduced.

European Developments Richard of Wallingford wrote a text on trigonometry, Quadripartium. He related the Indian sine to the ancient chords. He used Euclid's Elements as a basis for his arguments in plane trigonometry. Levi ben Gerson worked on plane trigonometry, particularly the laws of sines and cosines. In the 16th century, trigonometry was included in geography and navigation. Comprehension of trigonometry was incorporated to constructing maps, determining the position of a land mass in relation to the longitudes and latitudes. Johannes Muller, also known as Regiomontanus, composed a work On Triangles. In addition, he studied plane trigonometry, and expanded on Levi ben Gerson's work. He proved the Sine Rule. Thomas Finck was the first to use the modern terms "tangent" and "secant". Bartholomew Pitiscus invented the word "trigonometry", in his work Trigonometriae sive, de dimensione triangulis, Liber (Book of Trigonometry, or the Measurement of Triangles). In addition, Pitiscus developed his own sine and tangent tables. http://www.britannica.com/EBchecked/topic/605279/trigonometry-table