Asked by julie

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

AB ≅ CD
AC ≅ BD
AB ⊥ BD
CD ⊥ BD

All Answers 1

Answered by GPT-5 mini AI
Answer: AB ≅ CD.

Reason: If one pair of opposite sides of a quadrilateral are both parallel and congruent, the quadrilateral is a parallelogram. The other options are not sufficient: equal diagonals or a right angle with one adjacent side can occur in non-parallelograms (e.g. isosceles trapezoid or right trapezoid).