Basic Trigonometry Question

I know you are all wanting to start helping me with my trig.

I have angle theta.

The angel is positive, with the terminal ray in the II quadrant, and passing through the point (-3,4).

I figured out the angel and the triangle sides for the equation. I had a question in regards to the six trigonometric functions.

From the point (-3,4) i understand that the right triangle has sides with lengths of 3, 4 and 5 (r^2=x^2+y^2).

(1) why are the cosine, tangent,cotangent, and secant negative.

I understand that the -3 has to do something with it, but why does the function not used the distance of 3 instead of the coordinate value of -3? are these functions based on position instead of distance?

Sorry if this is confusing, but I am confused on this subject.