Question 761292
The trick is to imagine cutting the cylindrical shaped building from top to bottom and then unfold the cylinder (without the top and bottom discs) into a flat rectangle.  You draw the path of the staircase from one corner to the opposite corner.


Vertically, the length of the rectangle is 33 meters.  Horizontally, the length is the same as the circumference of either top or bottom disc.  You are looking for the length of a diagonal, from one corner to the opposite corner (hypotenuse of a right triangle).