​ Help with this trig problem

Using the Law of Sines to find the angle opposite the side of 15, we have

arcsin [ 15*sin (108) / 28 ]  ≈  30.63°

So...the remaining agle must be   = 180 - 108 - 30.63   ≈  41.37°

So......applying the Law of  Sines once more, we have

  x  / sin (41.37)   = 28 / sin (108)      ......  multiply both sides by  sin (41.37)

x  =   28* sin( 41.37) / sin (108)  ≈ 19.46