Question

Which pair of the dotted line, segments, in the following figure, are parallel. Give reason:

Answer 1

∠1 = 110° ......(vertically opposite angles)
If lines are parallel then
∠1 + 70° = 180° ........(co-interior angles)
⇒110° + 70°= 180°
⇒180° =180°
Which is correct.
∴ Lines are parallel.