[tex]\angle1\text{ and }\angle2\text{ are supplementary angles}[/tex][tex]\angle4=75^{\circ}(alternate\text{ angle)}[/tex][tex]\begin{gathered} \angle4+\angle1=180(supplementary\text{ angle)} \\ 75+\angle1=180 \\ \angle1=180-75 \\ \angle1=105^{\circ} \end{gathered}[/tex][tex]\angle2=75^{\circ}(\text{vertically opposite angle to }\angle4)[/tex]
