9514 1404 393
Answer:
2.89 m
Explanation:
The attached shows the figure drawn accurately. It also shows that the angle of the line of sight is 102° -90° = 12° below the horizontal. The sine relation is useful in this situation.
The side opposite the angle in the triangle of interest is the difference in building heights, 5.3 -4.7 = 0.6 m. So, the useful relation is ...
Sin = Opposite/Hypotenuse
sin(12°) = (0.6 m)/(PR)
PR = (0.6 m)/sin(12°) ≈ 2.886 m
PR ≈ 2.89 m
The distance to the subject is about 2.89 meters.