# Trigonometry & Astronomy

Topics: Trigonometry, Astronomy in medieval Islam, Sun Pages: 4 (1249 words) Published: July 15, 2011
The Way Trigonometry is used in Astronomy
By: Joanna Matthews
Mrs. Amy Goodrum
July 15, 2003
Abstract
This report is about how trigonometry is used in Astronomy. Even though trigonometry is applied in many areas, such as engineering, chemistry, surveying, and physics, it is mainly used in astronomy Trigonometry is used to find the distance of stars, the distance from one planet to another and from one plant to the sun. It is possible to find the radius of the Earth also. This report will basically give more insight in the way trigonometry and astronomy goes hand in hand. Background

Trigonometry comes from a Greek word "trigonometria" put together from these 3 words: Tri (three) gonia (angle) metro (measure). Trigonometry has been around for many centuries, but in 140 BC a man named Hipparchus apparently wrote 12 books on the table of chords and became the founder of trigonometry. He was the first Greek mathematician to study triangular geometry. This study led him to write the 12 books. Other people have added to Hipparchus’ work, but the two people that stands out the most are were Menelaus (ca. AD 100) and Ptolemy (ca. AD 100). Menelaus was a Greek mathematician that created six books on tables of chords. He created a couple of triangle properties. Menelaus had a big hand in spherical trigonometry also. He was like the one that was after Hipparchus’ work the most. Ptolemy was a Greek astronomer who was highly respected in his city because of his work. He was the first mathematician to complete the tables of chords, which were 13 books. Although his work had respect, there was controversy behind it. People said that he stole ideas and inventions to further his work. There was no proof of these accusations and his is still respected and appreciated. The Muslims, Chinese, Indians, and Babylonians had their own information that aided to trigonometry. The Muslims introduced the tangent...