If e || f and a || b, what is the value of y. *

Answer:
y = 90
Step-by-step explanation:
Since, e || f and a || b
Therefore, quadrilateral so formed is a rectangle.
Each angle of a rectangle is right angle.
[tex] \therefore \: y \degree = 90 \degree \\ \\ \huge \red{ \boxed{ \therefore \: y = 90}} \\ \\ [/tex]