Because this is a triangle, all three angles put together equals 180 degrees.
We can add the angles together and set them equal to 180 to solve for the value of y.
y + y - 12 + 56 = 180
Combine like terms.
2y + 44 = 180
Subtract 44 from both sides.
2y = 136
Divide both sides by 2.
y = 68
The value of y is equal to 68 degrees.