I've included a picture to illustrate.
We can see from the picture that we need to find side X of the triangle to be able to find side Y of the building.
[tex]tan18= \frac{2}{X} \\ X= \frac{2}{tan18} \\ X=6.16 m[/tex]
Now just find side Y:
[tex]tan61=\frac{Y}{6.16}\\ 6.16tan61=Y\\ 11.11m=Y[/tex]
Don't forget to add 2 m to 11.11 m for the total height of the building.
13.11 m is the height of the building.
