Given a parallelogram ABCD with the measure of segment BC = (6 - x) units, the measure of segment AD = (x + 2) units.
Angle A measures (100 - y) degrees and angle C measures (12 + y) degrees.
Recall that for a parallelogram, the opposite sides are of equal length and the opposite angles are of equal measure.
From the given parallelogram, segment BC is opposite to segment AD and angle A is opposite to angle C.
Thus, 6 - x = x + 2
2x = 4
x = 2
Therefore, the value of x is 2 and the length of segment BC is 6 - 2 = 4 units.
Similarly, 100 - y = 12 + y
2y = 88
y = 44
Therefore, value of y is 44 and the measure of angle DAB is 100 - 44 = 56 degrees.