Experts please help me solve this question..

Dear Student,
In case of refraction of light through a prism,
$$\begin{gathered} Angle of incidence \left(i_1\right) + Angle of emergence \left(i_2\right) = angle of prism \left(A\right)+angle of deviation \left(\delta \right) \\ Thus, \\ \delta =\left(i_1+i_2\right)-A \end{gathered}$$
Regards