Question 1100445
We can use force triangle in this situation. 

Using Cosine Law,
  R² = 55.9² + 42.3² - 2(55.9)(42.3)cos(124.5)
  R = 87.14

Using Sine Law,
  87.14/sin(124.5) = 55.9/sin(Ɵ)
  Ɵ; = 31.916 degrees