make yourself a sketch of the
30-60-90 ° and the 45-45-90 ° right angled triangles
the ratios of those sides are (in the same order)
1--√3--2 and 1--1--√2
so
sin30 = 1/2 --- csc30 = 2
cos30 = √3/2 --- sec30 = 2/√3
tan30 = 1/√3 ----cot 30 = √3
etc
you have to know the definition of the trig ratios in terms of their names of sides
e.g cos Ø = adjacent/hypotenuse
how to find the value of any standard angle ??? for example sin 60*??? without using table
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