I get zero for 2sin(3pi). There is no way the answer is 1.87.
6(pi)/5 = 1.2, right?
This is clearly miswritten. That "6 pi" looks like it should be in a trig function itself. And perhaps that "5" in intended to be inside the sine? I.e. 2 sin(2pi/5)?
Given your initial problem statement that won't matter...the only trig function you evaluated you set to 0 (correctly) so radian/degree mode will have no effect. I agree with HallsofIvy: Are you sure your problem is written correctly?