The angle 1 and 2 forms the linear pair on a straight line.
The value of angle 2 can be determined as,
[tex]\begin{gathered} \angle1+\angle2=180^{\circ} \\ 45^{\circ}+\angle2=180^{\circ} \\ \angle2=180^{\circ}-45^{\circ} \\ \angle2=135^{\circ} \end{gathered}[/tex]Thus, the value of angle 2 is 135 degrees.
