[tex]\sin \theta = \dfrac{\textrm{opposite}}{\textrm{hypotenuse}}[/tex]
[tex]\sin 35^\circ = \dfrac{x}{10}[/tex]
[tex]x = 10 \sin 35^\circ[/tex]
That's the exact answer; they usually want a calculator approximation at this point,
[tex]x \approx 5.735[/tex]
