We can use the tangent rule for this problem because the opposite x is unknown and adjacent side 10 is knwon. Since,
[tex] tan \theta= \frac{Opposite side}{Adjacent side} [/tex]
[tex] tan 35=\frac{x}{10} [/tex]
[tex] 0.474=\frac{x}{10} [/tex] Since tan 35°=0.474
[tex] 0.474*10=\frac{x}{10}*10 [/tex] Multiplying each sides by 10.
4.74=x
x=4.7 (Rounded to nearest tenth)