A bird watcher spots a sparrow in a tree. The sparrow sits in a nest that is 10.5 feet above the bird watcher's eye level, at a 35° angle of elevation from the bird watcher. The bird watcher then notices a hawk in the same tree, 7.4 feet above the sparrow, at a certain angle of elevation. The bird watcher stands 15 feet from the base of the tree. What is the angle of elevation from the bird watcher to the hawk?