physics (last problem)help
posted by RUdi .
On a calm, bright day, you're scuba diving in a deep lake (n = 1.33), 5.40 m from your sailboat. When you are 3.10 m below the surface, the top of the sailboat mast appears to you to be in a direction 40.0° from vertical. Calculate the height of the mast
part two
From your point of view, the entire sky appears to be confined to a bright disk directly above you on the surface of the water. Determine the diameter of this circle.
I draw a picture and i can use snell law but i am stuck at the trig part. Or my drawing is wrong help

Do you need help on part one or part two?
Part 1: The ray from the top of the mast that you see has an angle of incidence of
tan^1 = H/5.40. Tha angle of refraction is tan ^1 3.10/5.40 = 29.9 degrees
Now use Snell's law:
sin [tan^1(H/5.40)] = 1.33 sin 29.9
Solve for H
sin^[tan^1(H/5.40)] = 0.662
tan^1(H/5.40) = 41.4 degrees
H/5.40 = 0.884
H = 4.77 m
For part 2, assume that the angle of incidence for the sky above is 90 degrees at the edge of the circular disc. Solve for the angle of refraction and use that to get the diameter of the circle of light 
above answer is not correct