Answer:
y = 108°
Explanation:
Since AB and CD are parallel lines, then
3x - 12 and 2x + 16 are corresponding angles and congruent, thus
3x - 12 = 2x + 16 ( subtract 2x from both sides )
x - 12 = 16 ( add 12 to both sides )
x = 28
Thus
3x - 12 = 3(28) - 12 = 84 - 12 = 72°
y and 3x - 12 are adjacent angles and supplementary, thus
y = 180° - 72° = 108°