Therefore,
[tex]\cos \phi=\frac{Adjacent}{\text{hypotenuse}}[/tex]
But, we do not have the dimension for the hypotenuse, In order to find the hypotenuse, we need to apply the Pythagorean theorem
Hence,
[tex]\begin{gathered} \text{Hyp}^2=opp^2+adj^2 \\ \text{hyp}^2=4^2+3^2 \\ \text{hyp}^2=16+9 \\ \text{hyp}^2=25 \\ \text{hyp}=\sqrt[]{25} \\ =5 \end{gathered}[/tex]
Therefore,
[tex]\cos \phi=\frac{3}{5}[/tex]
