Hi Aspirant,

It is a chapter dealt in class 7-8.It accentuates the relation between angles of a triangle in terms of cosines,sines and tangents.You may also study about the inverse trigonemetric functions like cot,sec and cosec etc.Its a vety interesting chapter and it is required in almost every field of mathematics after class 9 onwards.SO study the chapter properly to avoid confusion in later classes.

Hope it helps!!