Answer
$\theta _{2}\approx 45^{0}=\dfrac {\pi }{4}$
Work Step by Step
$\dfrac {\sin \theta _{1}}{\sin \theta _{2}}=\dfrac {v_{1}}{v_{2}}\Rightarrow \dfrac {\sin 70}{\sin \theta _{2}}=1.33\Rightarrow \sin \theta _{2}=\dfrac {\sin 70}{1.33}\approx 0.707$
$\theta _{2}\approx \sin ^{-1}\left( 0.707\right) \approx 45^{0}=\dfrac {\pi }{4}$
