Can't really figure out this problem where I have to find side $RS$, this is covered in my high-school trig curriculum, and it is in the section which deals with all concepts before sine and cosine law, so likely they want as solution using none of cosine or sine law. Nonetheless if nothing works... cosine or sine law solutions would also be accepted :).
I just can't really get any info from here other than the fact that since the right triangles are right, and we know the angles, we can get info about the other triangle angle measures. That's all...