Two ships A and B with underwater sonar have located the wreckage, W, of an old ship on the sea floor.
The sonar bearing from both ships is due west of the wreck. When the distance AB between the two
ships is 8000 m, the angles of depression to the wreck are < 𝐴 = 18° and < 𝐵 = 56°. Determine the
depth of the water directly above the wreck
Draw a diagram and review the basic trig functions.
If the depth is d, then
d cot18° - d cot56° = 800