Discovering Trigonometry

Trigonometry is a category of mathematics that studies triangles, as well as the spatial relationships between triangle sides and degree angles between these sides. Trigonometry is used to define trigonometric functions.

Trigonometric functions describe the relationships between the angles and sides and are also applied to cyclical phenomena, such as waves.
Trigonometry itself is very similar to geometry, but is slightly more complex. It utilizes functions such as sine, cosine and tangent to analyze areas of angles. These and other functions of trigonometry are used in a variety of career fields including but not limited to: acoustics, architecture, astronomy, biology, chemistry, civil engineering, computer graphics, metrology, medical imaging, music theory and several other fields.

Trigonometry is taught starting in middle and high school. It can be taught as a separate course, but is also taught as a preliminary course for calculus. Trigonometry develops students knowledge of both pure and applied mathematics. College level trigonometry is required for several different career majors to help students develop a further understanding of angles and spatial relationships.

Trigonometry was first developed in the 2nd century BC by the Greek mathematician Hippachus. Hipparchus developed what is known as the first trigonometric table. He used trigonometry, and other mathematical functions, to develop lunar and solar theories. He also used trigonometry to study the motion and orbit of the sun and moon. Though trigonometry was developed by Hippachus, the study of triangles can be traced all the way back to Egyptian mathematics and Babylonian mathematics.

The Egyptians and Babylonians used trigonometry to develop theorems on ratios of triangle sides. The Babylonian astronomers used early trigonometry to measure the angular distances on the celestial sphere. They used this to detail records of rising and setting stars, planet motions, and solar and lunar eclipses.

During the Hellenistic period, the Greeks took the early Egyptian and Babylonian trigonometry and developed the chord, which developed the use of arcs. A chord of a circle is the geometric line segment whose endpoints are on the circles circumference. The chord joins two points on any curve, but it is not limited to an ellipse. The chord that passes through the center point of the circle also functions as the circles diameter.

The trigonometry that is currently used today was developed by European mathematicians, Sir Isaac Newton and James Stirling in the 17th century. Newton and Stirling created the general formulas that are currently used to solve trigonometric functions.