The diagram below shows the ray OP travelling through an equilateral prism of a certain material.

(a) Given,

angle of prism (A) = 60° for an equilateral prism.

angle of incidence (i₁) = 65°

Angle of deviation (δ) = 43°

𝑒 = i₂ = ?

From formula,

Angle of deviation (δ) = 𝑖 + 𝑒 − 𝐴

Substituting the values we get:

43 = 65 + i₂ - 60°

i₂ = 43 - 5 = 38°

Hence, i₂ = 38°

(b) Emergent ray