Trig Ratios can be difficult!
Although most of us are very familiar with the SohCahToa method of remembering Sine, Cosine, and Tangent, the real difficulty comes in naming the sides. Big deal if one knows, for example, that Sine = Opposite /Hypotenuse if one has trouble locating Opposite. So I have introduced the concept of "the hunt". The SohCahToa-nese, in my version of American History, did not hunt Bison, they hunted Hypotenuse. Place an arrow in the right angle depiction, and presto, there is hypotenuse. Now, on the hunt, one brave is always getting lost- so they have to 'call out' to him Opposite....Opposite....Opposite. As you do that, you draw the curved angle away like a 'sound wave', originating from where the angle where the 'hunt' is happening. Presto, Opposite is located. That leaves Adjacent, the brave who never leaves the chief's side.
I have found that this trick has enabled students to link the idea of Opposite, Adjacent, and Hypotenuse to the idea of what SohCahToa stands for, as well as having fun with the concept.