Find the critical angle and the angle of emergence

Question

A ray of light in water of Refractive index nw=1.33 is indecent on water-air interface. 

a) Find the critical angle of reflection

b) Find the angle of emergence at 40 degree angle of incidence in water

c) Find the angle of emergence/ Total reflection when the angle of incidence in water is 55 degrees

Answer 1

Critical angle inside water is 49 degree approx

sinC= 1/ R. I

for angle of emergence r

sin 49 / sinr = 1/1.33

find r as angle of emergence in sir