Since we're working on a right triangle, we'll have that:
[tex]\cos 78=\frac{x}{35}[/tex]
Solving for x,
[tex]\begin{gathered} \cos 78=\frac{x}{35}\rightarrow35\cos 78=x \\ \rightarrow x=7.3 \end{gathered}[/tex]
This way, the lenght of MK, to the nearesth tenth, is 7.3
