Sounds good to me. You shouldn't need to use trig functions manually, though. OpenGL has translate and rotate functions.
Typically the way you draw an object is to push a matrix, apply the translations and rotations to where you want the object to be, draw the triangles and textures, and then pop the matrix, so you're back at the origin ready to draw the next object. So, OpenGL takes care of all the linear algebra and trig for you.