Light in air strikes a water surface at the polarizing angle. The part of the beam refracted into the water strikes a submerged slab of material with refractive index n = 1.53 as shown in the figure below. The light reflected from the upper surface of the slab is completely polarized. Find the angle θ between the water surface and the surface of the slab.

Light in air strikes a water surface at the polarizing angle. The part of the beam refracted into the water strikes a submerged slab of material with refractive index n = 1.53 as shown in the figure below. The light reflected from the upper surface of the slab is completely polarized. Find the angle θ between the water surface and the surface of the slab.