Remember SOHCAHTOA
Sine- opposite/hypotenuse
Cosine- adjacent/hypotenuse
Tangent- opposite/adjacent
Look at the angle (x) you are trying to figure out and pick which one of these it is.
In your calculator, do the equation first to get a decimal
Then press whichever one you chose on the calculator, so if you got like 0.2 by doing opposite/adjacent for tangent, you would type in 0.2 and then the TAN button
hope this makes sense!!