Question

line l is parallel to line m and line n is paralle to line p find angle a

Answer 1

Suppose if possible line p is not intersecting line q , then line p is parallel to line q

Given line p is parallel to line l  ......(1)

 Also line p is parallel to line q by construction  .....(2)

 Therefore line l is parallel to line q (by (1) and (2))

 Line l and m intersects each other implies line q and line m also intersects each other but that would lead to contradiction to given statement that line q is parallel to line m

Hence our assumption was wrong

Therefore line p is intersecting line q