Answer
$63^{\circ}$
Work Step by Step
We know that
$F=ILBsin\theta$
This can be rearranged as:
$sin\theta=\frac{F}{ILB}$
$\implies \theta=sin^{-1}\frac{F}{ILB}$
We plug in the known values to obtain:
$\theta=sin^{-1}\frac{1.6}{(3.0)(1.2)(0.50)}$
$\theta=63^{\circ}$