Explanation:
BCD = 180- 100 = 80
the opposite angles of a parallelogram are of equal measure
SO DAB = X = 80
The sum of all parallelogram angles = 360
360 - 160 = 200
200 equals the measure of angle ADC + ABC
ABC = ADC
200 = 2ABC
ABC = 100
ADB = DBC = 30
Y = 100 - 30 = 70
another way to find y is using the rule that says that the sum of the triangle ADB angles = 180
180 = 80 + 30 + y
y = 70