Answer:

Step-by-step explanation:
According to Snell’s Law we have the following:
(1)
Where:
is the first medium index of refraction (air)
is the second medium index of refraction (water)
is the angle of the incident ray
is the angle of the refracted ray
So, we need to find from (1):
(2)
(3)
Finally:
This is the angle of refraction