Question 891916
{{{drawing( 400, 400, 0, 200, 0, 200,
  rectangle( 20, 20, 120, 55 ),
  triangle( 20, 55, 120, 55, 120, 90 ),
  triangle( -8, -5, -3, -4, -7, 0 ), 
  locate(70,53,20 ),
  locate(125,77,y),
  locate(125,43,1.8),
  locate(35,62,38dgr)
  )}}}


The two bottom corner angles are both 90 degrees.  The angle at the upper right corner is the complement of the angle of elevation, so that is {{{90-38=52}}} degrees.


The segment on the right side of the triangle is the difference between building height and Jeff's height.  Call this y, and then y+1.8 is building height.  You first want to get y.


{{{y/20=tan(38)}}}
{{{y=20*tan(38)}}}
The building's height is {{{highlight(1.8+20*tan(38))}}}.