Answer
$$\theta \approx 44 ^o$$
Work Step by Step
1. Use the law of sines to calculate $\theta$:
$$\frac{sin \space 120^o}{45} = \frac{sin \space \theta}{36}$$ $$\frac{sin \space 120 ^o}{45} \times 36 = sin \space \theta$$ $$\theta = sin^{-1}(\frac{sin \space 120 ^o}{45} \times 36 ) \approx 44^o \space $$
