Answer
a) $\theta_2=26.6^o$
b) $\theta_3=31.2^o$
c) $\theta_4=31.2^o$
Work Step by Step
$n_1\sin(\theta_1)=n_2\sin(\theta_2)$
a) $\theta_2=\arcsin(\frac{n_1\sin(\theta_1)}{n_2})=\arcsin(\frac{1.0\sin(43.5^o)}{1.54})=26.6^o$
b) $\theta_3=\arcsin(\frac{n_2\sin(\theta_2)}{n_3})=\arcsin(\frac{1.54\sin(26.6^o)}{1.33})=31.2^o$
c) $\theta_4=\arcsin(\frac{n_1\sin(\theta_1)}{n_3})=\arcsin(\frac{1.0\sin(43.5^o)}{1.33})=31.2^o$
