how to learn trignometry ratios suggest smple method
Look at the following figure.
Here, ABC is a right-angled triangle such that angle B = 90°.
Let us represent perpendicular by P, base by B and hypotenuse by H.
Then simple method to learn the ratios is as follows:
Also, below given table represents the values of different trigonometric ratios at few specific angles.
You just learn the values for sin A and the you can calculate the rest on you own.
For example, if you write the values of sin A in reverse order in the table then you will get the values of cos A.
tan A can be calculated from the formula sin A/ cos A.
Remaining ones such as coesec A, sec A and cot A are just reciprocals of sin A, cos A and tan A respectively.
Hope it helps.