Don't we all wish we can go back to the days where all we had to solve was 2x+7=14? Good and bad news. Good being we get to go back to these kinds of problems
Now the bad news is that it involves trig. Don't be scared yet, its the same basics as solving a regular linear equation. These problems tend to look like: Sin(∅)+2=3.
The first step to solving this is to get sin alone. So we subtract two from both sides. Once two is subtracted you are left with: sin(∅)=1. This is where our handy dandy unit circle comes into play. We look to see at what angle sin equals 1 which only happens at 90° this means our answer is 90°.
Like everything in math, these problems can get a lot more complex and can have multiple answers. For example if after you've simplified your answer is cos(∅)=√2/2 then you are looking for every where that cosine = √2/2. In this case that would be both at 45° and 315°.
These problems aren't that hard to figure out, with a little practice you will know where every single angle is, no problem!