The opposite side to the angle of elevation is the height of the building and the side adjacent to the angle is the distance of the engineer to the base. The trigonometric function that represents the situation is tangent.
tangent 38° = opposide side / adjacent side
tangent 38° = 300 ft / x ft
The value of x from the equation is 383.98 ft. Thus, the engineer is 383.98 ft.