Two equilateral-triangular prisms
\(P_1 \)and
\(P_2\) are kept with their sides parallel to each other, in vacuum, as shown in the figure. A light ray enters prism
\(P_1\) at an angle of incidence 𝜃 such that the outgoing ray undergoes minimum deviation in prism
\(P_2\). If the respective refractive indices of
\(P_1\) and
\( P_2\) are
\(√ 3 /2\) and
\(√3\), then
\(\theta = sin{−1}[\sqrt \frac{ 3}{ 2} sin ( \frac{\pi}{B} )],\) where the value of
\(\beta\) is ______.