The angle between any two lines is equal to the angle between their perpendiculars. ∴i=30∘
From Snell's law, we have 1.51=sinrsin30∘ ⇒sinr=0.75 or r=48.6∘
Therefore, θ=r−i =48.6∘−30∘=18.6∘ ∴ Required angle between two emergent rays =2×18.6∘ =37.2∘C≈37∘