Which function is not the same as the other 3?

How to do this , and can some one explain

Abird on top of a 200 ft bridge tower sees a man standing on the lower part of the bridge (which is 50 ft above the ground). the angle of depression from the bird is 26 ̊. how far is the man from the base of the bridge tower? with explanation and pictures .

Find the missing factor. write your answer inexponential form.9^2=9^4×