List of Lessons For The Basics Of Trigonometry

Introduction to Trigonometry

Trigonometry is the branch of mathematics which deals with only right angled triangles. It gives a relationship between angles and sides of the triangle which are related to each other with trigonometric ratios.

The word "Trigonometry" comprises three Greek words, "Tri", "gon" and "metron". The meanings of these in English are "three", "sides" and "measure" respectively. The collective meaning of these words in Greek denotes "measure of three sides".

Early astronomers used trigonometry to find out the distances of stars and planets from the earth. Also, it has been in use in disciplines of engineering and physical sciences till now. The earliest works were recorded in Egypt and India. After that Euclid and Archimedes studied it further and proved theorems that we see in modern trigonometry formulae. The modern definition of sine was first developed by Indian mathematician Aryabhata in the 5th century.

There two types of trigonometry that is studied: planar and spherical trigonometry.

1. Planar trigonometry

   Planar trigonometry is the branch of trigonometry which deals with study of angles and sides of triangles on two dimensional.

2. Spherical trigonometry

   Spherical trigonometry as the name suggests deals with study of angles and sides of triangles formed on a sphere. Astronomers relies on it to solve calculations related to space objects like stars, planets, moons etc.