Answer:
0.0349207695 mi
Explanation:
Well, I guess you start with a triangle. 
Let O be the point 1 mile from the building. 
Let B be the bottom of the building 
Let H be the top of the building. 
Angle HOB is given (2 degrees) 
Side OB is given as 1 mile (5280 feet) 
So side BH = the height of the building 
tan(HOB) = BH / OB 
BH = OB * tan(HOB)