# A Host of Scholars Contributed to Inventing Trigonometry

Daily Herald (Arlington Heights, IL), January 21, 2016 | Go to article overview

# A Host of Scholars Contributed to Inventing Trigonometry

Wanting to determine distances between stars, across land and sea, ancient Greeks developed trigonometry -- triangle measure.

Before 100 B.C., scholars including Hipparchus and later Ptolemy and Menelaus contributed to the mathematical invention. Hipparchus initiated the use of chords, a key component of trigonometry, to measure angles within a circle. Ptolemy, using older Babylonian strategies, refined the chord concept.

By A.D. 1000, Arab and Indian mathematicians improved Greek trigonometry calculation methods.

The general trigonometry concept of the relationships between lengths of triangle sides and angle measurements dates to even earlier times. Ancient Egyptians created formulas to determine the slope of an incline for use in constructing pyramids.

The Rhind Mathematical Papyrus, written by an Egyptian scribe in 1650 B.C. and accessible online at the British Museum website, includes a kind of math quiz with problems and solutions for determining triangle measurements. This math how-to is a copy of an older papyrus that dated to 1800 B.C.

"Trigonometry is, of course, very old, and no single person could be said to have discovered it. It is a subject with many applications in the sciences and engineering." said Lynn Narasimhan, director and professor of the college of Science and Health at DePaul University,

Trigonometry uses ratios called sine, cosine, tangent, cotangent, secant, and cosecant to determine the length of unknown triangle sides or angle degrees within a triangle.

Prior knowledge of algebra and geometry is needed before applying trigonometry calculations. Generally called trig, it is usually taught in the junior year of high school and is sometimes called Algebra 3 or Advanced Algebra/Trig. …

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