Let the missing angle in the outer angle be a. Now since l1 is parallel to l2, hence the missing angle in the inner figure is a as well
corresponding angles when a transversal cuts through two parallel lines are equal\(2(x+y) + a = 360\)
Quote:
Sum of all the angles in a quadrilateral
\(a=360-2(x+y)\)
♦Now if we sum all the angles of the outer figure we have:-
\(z+3x+y+a = 360\)
Putting a as highlighted by the equation in the diamond above:
z=y-x
Hence option E is the correct answer.