Memory Tricks for Trigonometry

In the post titled Trigonometry Formula Memorization Trick, I agreed to write about a simple memory trick for memorizing the value of all major angles of different trigonometry ratios like sin30, cos45, tan60, etc. So here you go –

Values of Trigonometric Angles

Let’s start with most commonly used angles of Sin. The angles are 0°, 30° (?/6), 45° (?/4), 60° (?/3), 90° (?/2). For these angles we’ve to make fractions for which we’ve to write 0, 1, 2, 3 and 4 in the numerators and write 4 in the denominator of each fraction. After that take the square root of each of these fractions and there you are. Refer to the table below for better understanding.

For Cosine we simply have to write the results of Sin in reverse order. Refer to the table below. The values in the Cos row is in reverse order to that of Sin row.

Tan is very simple. You just have to remember that Tan=Sin/Cos. Hence, to get the value of Tan we’ve to divide values of angles of Sin from SinA row by values of angles of Cos from CosA row.


I am glad that of late, many readers have started participating actively in discussions (comments) under various posts. A quick calculation trick/technique/method from your side can also be posted on You just have to write it properly and send it to me at  Don’t forget to write a brief description (2-3 lines) of yours, to be added at the end of the post.

  1. kai
  2. Ankit
  3. knn mayya
  4. Shaun
  5. pessimist
    • Ruchir sahoo
  6. Biswo Jha
  7. ABBAS
    • debasis
  8. sumith
  9. kiran

Leave a Reply

Your email address will not be published. Required fields are marked *