Question

in the figure 6.6 which of the two lines are parallel and why?

Answer 1

if the sum of co-interior angles of two lines is 180° then the lines are parallel.
this is satisfied only by a).that's y (a) is ur answer

Answer 2

l and m are parallel.. because for two parallel lines intersected by a transversal the sum of interior angles as shown here is 180. (132+48 = 180) . but that is not so with other line .. here sum is 179 so they are not parallel.