Sine and cosin functions are cyclic. In other words they repeat themselves in every 2*pi angle. So
sin (101pi/6)= sin (5pi/6) ->(101*pi/6) - (16pi)
Sin (5pi/6) is in second quadrant so Sin (5pi/6)= Sin (pi/6) = 1/2.
Remember special triangles (30-60-90) (45-45-90) ,if you do not know the value of functions. Dr. Reo forgot to put pi to his answer.
Hopefully this helps.