Answer:
a The diagram of the situation is shown on the first uploaded image
b the angle of incidence beam striking the water is 
c the angle of refraction beam striking the water is 
d The angle the refracted beam make with respect to the horizontal is 
e The height of the target above sea level is

Explanation:
From the diagram we see that the angle of the beam striking the water is



According to Snell's law

Where
is the refractive index of water = 1.333
is the angle of incidence
is the refractive index of air = 1
r is the angle of refraction
Substituting values accordingly

Making r the subject of the formula


looking at the diagram we can see that to obtain the angle the refraction beam makes with the horizontal by subtracting the angle refraction from 90°
i.e
°
From the diagram we see that the height target above sea level can be obtained by this relation

Where h is the is the height


