Answer:

Step-by-step explanation:
From the question we are told that:
Height 
Angle of depression 
Angle of Elevation 
Generally the equation for the vertical distance between Emery's distance x and the bottom of the building is mathematically given by
Since the angle of depression and elevation are given as
27 and 23 respectively
Therefore
Emery's view of the 42 ft building is


Therefore Emery's distance x to the base of the building h' is


Generally the Trigonometric equation for Emery's distance x is mathematically given by


