We are given that
line(l) and line(m) are parallel to each other
and we have to find m< 4
we can see that m<3 and m<4 forms linear pair
since, they form linear pair
so, the sum of both angles must be 180°
so, we can write as
m<3 +m<4=180°
we are given
m<3=50°
now, we can plug it
50°+m<4=180°
now, we can solve for m<4
and we get
50°+m<4-50°=180°-50°
m<4=130°......................Answer
