Answer:
AB║CD and AD║BC
Explanation:
By the property of a parallelogram,
" Consecutive angles of a parallelogram are supplementary"
In the figure attached,
∠DCB and ∠CDA are the supplementary angles. Therefore ABCD will be a parallelogram.
[Given: m(∠DCB) + m(∠CDA) = 180°]
And the pair of opposite sides of the parallelogram ABCD will be parallel.
AD║BC and AB║CD