Introduction to Trigonometry
Trigonometry is the branch of mathematics which deals with only right angled triangles. It gives relationship
between angles and sides of the triangle which are related to each other with trigonometric ratios.
The word "Trigonometry" comprise of three greek words, "Tri", "gon" and "metron". The meaning of
these in english are "three", "sides" and "measure" respectively. Collectively 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.
Trigonometry topics list
- Trigonometric ratios
1. Trigonometric ratios
Trigonometric ratios are the different standard combinations of ratios of the sides of a right angled triangle defined in relation to one of its two acute angles. There are following six such trigonometric ratios in trigonometry:
- Sine
- Cosine
- Tangent
- Cosecant
- Secant
- Cotangent
How to calculate the ratios and mnemonics to remember them have been explained in detail in the chapter Learn Trigonometric Ratios, Formulas And Calculations.
