Question 366437
the diagonal brace =150 feet
the vertical height on the side of bridge = x 
the horizontal height = x +30
..
they form a right triangle.
use pythagoras formula
x^2+(x+30)^2=150^2
x^2+x^2+60x+900=150^2
2x^2+60x+900=22500
2x^2+60x-21600
/2
x^2+30x-10800
x^2+120x-90x-10800=0
x(x+120)-90(x+120)=0
(x-90)(x+120)=0
x= 90 vertical distance
horizontal = 90+30 =120 feet
...
m.ananth@hotmail.ca