A lighthouse observatory is 1874 meters above sea level. The lighthouse keeper
sees two boats sailing away. The angle of depression to the boat that is furthest
away from the lighthouse keeper is 11°. The angle of depression to the boat that is
closer to the lighthouse keeper is 41.3°. How far apart are the boats' sterns (the
rear of the boats), in meters? Let a be the distance between the boats' sterns, in
meters. Assume the two boats and lighthouse lie in the same plane. Round your
answer to one decimal place.

X = ?
If you can help me understand, thank you!