The joined angles are equal to 72 degrees, thefore the sum of GAF and FAE must be equal to that:
[tex]\measuredangle GAF+\measuredangle FAE=72\degree[/tex][tex]\begin{gathered} x+18+(x-6)=72 \\ 2x+18-6=72 \\ 2x+12=72 \\ 2x=72-12 \\ 2x=60 \\ x=\frac{60}{2}=30 \end{gathered}[/tex]The values of GAF and FAE.
[tex]\begin{gathered} \measuredangle GAF\text{ = x-6 = 30-6=24} \\ \measuredangle FAE=x+18=30+18=48 \end{gathered}[/tex]