Two birds sit at the top of two different trees 17.8 feet away from one another. The distance between the first bird and a bird watcher on the ground is 37.4 feet. What is the angle measure, or angle of depression, between this bird and the bird watcher? Two trees have a bird on top of each. Distance between birdwatcher and first bird is 37 point 4 feet. Distance between each bird is 17 point 8 feet. Angle of depression between birdwatcher and first bird is unknown.