The little lines through the two sides mean they are the same length.
When the two sides are the same length the 2 corresponding angles are also the same, so Angle A and Angle B are both 34 degrees.
The three inside angles of a triangle equal 180, so angle C = 180 - 68 = 112
Angle C is given as 4y, so 4y = 112
Divide both sides by 4:
y = 112 / 4
y = 28
