Question

If two lines are parallel then prove that the sum of co interior angle is 180°

Answer 1

45*45*45 the angle of that two bisecting lines

Answer 2

let AB and CD be two line parralel to each other
construction - draw a line PQ intersecting AB and CD

now since AB ll CD and PQ intersects then therfore PQ is transversal
therefore angle APQ + angle CQP =180 ( Angles on the same side of transversal or we can say Co interior angles