Question 1190408
<br>
The description is not perfectly clear....  I will assume the 9.45 meters and 2.75 meters are the distances from Madeline and the building from the X -- and not the distances to the edges of the mirror.<br>
Use corresponding parts of similar triangles.<br><pre>
    Madeline's eyes height         building's height
  -------------------------- = --------------------------
  Madeline's distance from X   building's distance from X

   1.55     x
   ---- = ----
   2.75   9.45

x = ((1.55)(9.45))/(2.75)<br></pre>
Use a calculator....<br>