First, we find the angle there using the cosine function
[tex]\begin{gathered} \cos \theta=-\frac{1}{4} \\ \theta=\cos ^{-1}(\frac{1}{4})=75.5 \end{gathered}[/tex]So, the angle is 75.5°.
Then, we find the tangent of theta
[tex]\tan \theta=\tan (75.5)=3.9[/tex]