If you read the first post, I do state it's a parallelogram by stating AD || BC and AB || DC.

Hi, jallenmorris,

The last version of the pic., again, does not give sufficient info:

you can change the angle BAD, and obtain different values of parallelogram’s area.

The fact that in your picture B is strictly above D does not help: it could be merely a coincidence. So in the end the picture doesn’t let us to correctly infer that ABD is right triangle. On real GMAT pictures, all measures that intended to be fixed, are explicitly fixed.

So I think this would be somewhat more proper picture:

Attachment:

The attachment **GMATQuestionBestPicture_edit.gif** is no longer available

Also, you need to state that ABCD is parallelogram.