10th Class Mathematics Introduction to Trigonometry Introduction

      Introduction

The word trigonometry is a Greek word consists of two parts 'trigon' and 'metron? which means measurements of the sides of the triangles. This was basically developed to find the solutions of the problem related to the triangles in the geometry. Initially we use to measure angles in terms of degree, but now we will use another unit of measurement of angles called radians. We have/ n radian \[={{180}^{o}}\]

\[{{1}^{o}}={{60}^{/}}\], where dash denotes minutes and 1' = 60", where the double dash denotes seconds. The relation between the radian and degree measure is given by:

1  radian \[=\left( \frac{{{180}^{o}}}{\pi } \right)\,and\,{{1}^{o}}\frac{\pi }{180}\]radians