[tex]cos30 = \frac{cat.adjacente}{hipotenusa} \\ \\ cos30 = \frac{15}{x} \\ \\ \frac{ \sqrt{3} }{2} = \frac{15}{x} \\ \\ \sqrt{3} x = 30 \\ x = \frac{30}{ \sqrt{3} } \times \frac{ \sqrt{3} }{ \sqrt{3} } \\ \\ x = \frac{30 \sqrt{3} }{ \sqrt{9} } \\ \\ x = \frac{30 \sqrt{3} }{3} \\ \\ {\boxed{\sf \ \red{x = 10 \sqrt{3}m }}}[/tex]
espero ter ajudado!
