The angle of interest is the one at the end of the shadow looking up toward the flagpole. Thus the length adjacent to the angle is that of the shadow, 22 ft. The length opposite the angle is the height of the flagpole, 45 ft. The tangent of the angle is the ratio of the opposite length to the adjacent one.
... tan(angle) = (45 ft)/(22 ft)
... angle = arctan(45/22) ≈ 63.9° . . . . . matches selection A.
