Always, always, the sine of an angle is equal to the opposite side divided by the hypotenuse (opp/hyp in the diagram).

Is sin OPP over adjacent?

Using these names we can list the following standard ratios: sinθ=oppositehypotenuse,cosθ=adjacenthypotenuse,tanθ=oppositeadjacent.

What is opposite over HYP?

Sine = Opposite / Hypotenuse.