Trigonometry, the branch of mathematics concerned with specific functions of angles and their application to calculations. It is one of the interesting branches of mathematics. Trigonometry is about right-angled triangles, where one of the internal angles is 90° Moreover there is a fixed relation between the length of sides of the right angles triangle and angles between those sides.  If we know one angle and one side it easy to find out all sides and angles of the right angles triangle. The names of common trigonometric functions are sine (sin), cosine (cos), tangent (tan), cosecant, secant (sec), and  cotangent (cot)


There are many uses of the study of Trigonometry.

  • Trigonometric functions are used to describe the sound and light waves.
  • The calculus is based on it.
  • In oceanography trigonometry is useful. to estimate heights of waves and tides in oceans.
  •  In the creation of maps, in measuring the height of a building or a mountain we use trigonometry.
  • We use trigonometry in astronomy. We can find the distance between the earth and the stars.


This is a  table where we can easily get functions of sine, cos, tan.cot, sec, and cosec for special angles..

A student must memorize the table. It is the simple tool to solve trigonometric problems.