Inactive Tutor answered 06/10/22
The gentleman above has given you all the information you need.
Now you have two equations that equal h.
So you can rewrite the equations as:
(x-1000)tan15 = xtan11
xtan15 - 1000tan15 = xtan11
x (tan15-tan11) = 1000
x = 1000 / (tan 15-tan 11)
Solve for x, then solve for h.
Good luck!