Question

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

Answer 1

B. AC ≅ BD

Explanation:

Since the definition of a parallelogram literally says that it's a quadrilateral with 2 parallel sides, we have AB || CD so the 2 other sides (AC and BD) need to be either similar or parallel (either works, due to that if they're similar we can prove that since AB || CD that they're parallel).

Answer 2

The answer is B AC ≅ BD Since you already know that ab ll cd, all you need to know is that ac is bd