You must use cosine.
[tex]cosine\alpha=\dfrac{adjacent}{hypotenuse}[/tex]
We have α = 29°, adjacent = x and hypotenuse = 500 ft.
[tex]\cos29^o\approx0.8746[/tex]
Substitute:
[tex]\dfrac{x}{500}=0.8746[/tex] mutiply both sides by 500
[tex]x=437.3\ ft[/tex]
