51 feet
Explanation:height of boy = 6 ft
shadow of boy = 10 ft
let the height of flag pole = y
shadow of the pole = 85 ft
height of boy/shadow of boy = height of flag/ shadow of flag
[tex]\frac{6}{10}=\frac{y}{85}[/tex]cross multiply:
6(85) = y(10)
510 = 10y
DIvide both sides by 10:
510/10 = 10y/10
y = 51
Hence, the height of a flag pole that casts a shadow of 85 ft. long is 51 feet
