What is the value of y?

For this case we have by definition, that the sum of the internal angles of a triangle is 180 degrees.
Then, according to the figure we have to:
[tex]x + y + y = 180[/tex]
Where "x" represents the angle of the left side of the triangle, we have that "x" is given by:
[tex]x = 180-114\\x = 66[/tex]
So we have to:
[tex]66 + 2y = 180\\2y = 180-66\\2y = 114\\y = \frac {114} {2}\\y = 57[/tex]
Finally, "y" is equal to 57 degrees.
Answer:
Option C