Given: Angle of incidence i = 58º Reflected and refracted rays are perpendicular. Since the angle between the reflected ray and the normal is also 58º \(r + 58^\circ = 90^\circ\) \(r = 32^\circ\) Using Snell's law: \(n=\frac{\sin i}{\sin r}\) n= \(\frac{\sin58^\circ}{\sin32^\circ}\) n \(\approx \frac{0.848}{0.530}\) = 1.6 So, the refractive index of the glass relative to air is 1.6.