see the attached figure to better understand the problem
let
alfa--------> the angle of depression
we know that
in the right triangle ABC
sin alfa=opposite side angle alfa/hypotenuse
opposite side angle alfa=AB--------> 45 yd
hypotenuse=AC-------> 200 yd
so
sin alfa=45/200
alfa=arc sin (45/200)-----------> alfa=13.002°------> alfa=13°
therefore
the answer is
the angle of depression is 13 degrees