∠120 and ∠C are corresponding angles, therefore:
[tex]\angle C=120[/tex]∠30 and ∠A are corresponding angles, so:
[tex]\angle A=30[/tex]∠30 and ∠D are vertical angles, so:
[tex]\angle D=30[/tex]∠B and ∠120 are supplementary angles, so:
[tex]\begin{gathered} \angle B=180-120 \\ \angle B=60 \end{gathered}[/tex]∠B and ∠F are corresponding angles, so:
[tex]\angle F=60[/tex][tex]\begin{gathered} \angle E=\angle B+\angle A \\ \angle E=60+30 \\ \angle E=90 \end{gathered}[/tex]