Question

In quadrilateral ABDC, AB ∥ CD. Which additional piece of information is needed to determine that ABDC is a parallelogram?  i need help asap

Answer 1

ac would have to be equivalent to bd so your answer would be: the additional piece of information needed is ac=bd

Answer 2

Answer:  The answer is AB = CD.

Step-by-step explanation: We are given a quadrilateral ABCD with AB ║ CD.

We know that a quadrilateral is said to be a parallelogram if any one of the following conditions is satisfied:

(i)  If both pairs of opposite angles of a quadrilateral are equal, then it is a parallelogram.

(ii) If one pair of opposite sides of a quadrilateral is both equal and parallel, then it is a parallelogram.

(iii) If the diagonals of a quadrilateral bisect each other, then it is a parallelogram.

We are given that AB is parallel to CD, so by the condition (ii), if we get the additional information that AB = CD, then ABCD will be a parallelogram.

Thus, the answer is AB = CD.