Two parallel lines A and B are crossed by another line as shown in the attached figure. Angle 2 and 3 are equal, because they are opposite angles, while angle 3 and 7 are also equal, because they are corresponding angles, thus it is deduced that
angle 2 = angle 3
angle 3 = angle 7
So angle 2 = angle 7
<span>Hence fourth option is right.</span>
