What we really need to be learning instead is a thing called TRIGONOMETRIC SCALARS. sin, cos and tan are all still there, opposite, adjacent and hypotenuse are all here too. It's just a different, and BETTER way of thinking about the relationship between the angles and sides of a right angle triangle. This new way of thinking will make your life easier and better, especially when you move on to learning about vectors in component form later in your school career.
A video version of this blog post by David Butler, The Trig functions are about multiplication.
26 October 2021 Edit: 26 October 2021