Respuesta :

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]