Pool depth from refraction at 18 degrees viewing angle

[Huskies213]

Homework Statement

The bottom edge of the opposite side of an in-ground pool (n=1.33) is just visible at an angle of 18 degrees above the horizon. If the pool is 2m wide what is the depth?


I think I'm stuck on trying to relate the refraction formulas as to determining depth. .. any tips or help?

 

[dlgoff]

Make a cross-section drawing (of the pool and air above it) with a ray going from the bottom edge of the pool on one side, to the top edge of the pool on the other side. From there, draw the refracted ray. Can you now see how to find the depth from the angle and distance given?