There are three major trignometric ratios in mathematics and they are:
sine(sin), cosine(cos) and tangent(tan). A popular acronym is used in recalling the formula for each ratio and it is: SOH-CAH-TOA.
Sine(x) = Opp/Hyp
Cosine(x) = Adj/Hyp
Tangent(x) = Opp/Adj
Now, the Hyp is the hypothenus of the triangle and it is the side opposite to angle 90. The opposite and adjacent is kind of relative depending on the angle been considered. For this case, we are considering angle 30 which the opposite side is 60 and the remaining side becomes the adjacent
