Answer :
According to the problem,
[tex]\begin{gathered} m\angle8=23 \\ \end{gathered}[/tex]We have one pair of parallel lines and one transversal line.
Since those lines are parallel all 8 angles are related someway.
In the given graph, we have vertical angles, corresponding angle, alternate interior angles, alternate exterior angles, supplementary angles.
We know that
[tex]m\angle8=m\angle6=23[/tex]Since they are vertical angles.
Then, we have.
[tex]m\angle6=m\angle4=23[/tex]By alternate interior angles.
Also,
[tex]\begin{gathered} m\angle4+m\angle5=180 \\ 23+m\angle5=180 \\ m\angle5=180-23 \\ m\angle5=157 \end{gathered}[/tex]By same-side interior angles.
Then,
[tex]m\angle7=m\angle5=157[/tex]By vertical angles.
Additionally,
[tex]m\angle3=m\angle7=157[/tex]By corresponding angles.
Now, we have.
[tex]\begin{gathered} m\angle1=m\angle5=157 \\ m\angle2=m\angle6=23 \end{gathered}[/tex]By corresponding angles.