Make a drawing with a right triangle.
The opposite side, y, is the height of the dam less 1.65 m
The base or adjacent side is 90 m
The angle between the two sides is 90 m.
Then tan (26) = y / 90
y = 90 tan(26) = 90 (0.4877) = 43.90 m
The height of the dam is 43.90m + 1.65m = 45.55 m
        
             
        
        
        
1 foot<span> = </span>12<span> inches
</span>864/12=72 T<span>he window is 72 square feet.
A man uses </span>8 pieces of glass per square foot to make a stained glass window. So he needs to use 72*8=576 <span>pieces of glass.</span>
        
             
        
        
        
So you would do is take 3,500 and multiply it by 4% to get 140