how do you set up a trig problem. How do you know if its sin cos or tan

Adjacent and opposite are just normal words.

The house block opposite yours is across the street.  Your properties do not actually touch.

The house block adjacent to yours is the one that shares a common fenceline.

You learn this in maths classes at school, in manageable increments year by year. It starts with the study of triangles, and progresses to the study of sine, cosine, and tangent. If you fall behind at any time, it is easy to lose confidence and thereafter have a mental block which causes you to find some topics in maths difficult. Try to always keep up with the class, confidence is a big factor in your success in studying maths at school.

Good luck!  

When you have a right triangle, label the hypotenuse.

Then, look at the angle that you know (or want to know). From this angle, label the opposite side (the side across the triangle from the angle that you know) and label the adjacent side (their are two sides that touch the angle that you know, one is the hypotenuse, the other is the adjacent side).

If you know both the opposite side and the hypotenuse, use sin.

If you know both the adjacent side and the hypotenuse, use cos.

If you know both the opposite side and the adjacent side, use tan.