Answer:
Explanation:
Opposite sides are parallel and equal. So, ABCD is a parallelogram
In ΔABD,
∠A + ∠ACB + ∠ABC = 180 {Angle sum property of triangle}
∠A + 80 + 20 = 180
∠A + 100 = 180
∠A = 180 - 100
∠A = 80
In parallelogram, opposite angles are equal.
∠D = ∠A
x° = 80°