We can solve the length of u using Laws of Cosine since we are given with lengths of two side and one angle. The solution is shown below: cos U =( s²+t²-u²)/2st cos 37°= (9²+15²-u²)/2*9*15 0.79863*270=306-u² u²=306-215.63 u=9.5 units Therefore, the length of u is 9.5cm.