It is given that two lines A and B are parallel.
The one angle given is , 55 deg.
From the alternate opposiye angles,
[tex]\angle3=55^{\circ}[/tex]
And from the corresponding angles property, the angle 3 is corresponds to angle 7.
[tex]\angle3=\angle7=55^{\circ}[/tex]
Hence the value of angle 7 ,
[tex]m\angle7=55^{\circ}[/tex]
