How to create Mark Region element from Dynamo?

How to create Mark Region element from Dynamo? Criteria is create from intersection point of each wall, same the example follow (Fig. 01).

Cuz I’m a beginner, I try to do it in (Fig. 02). I think it a incorrect method and it can’t complete my purpose.

Fig. follow this link https://www.dropbox.com/sh/zs7yuhgia8a1xjx/AADRJx-nChlme8MgSzO6TZ6oa?dl=0

Please help me to solve my problem, thank you so much.

Your link is broken please re-post the link if you want others to help you.

Sorry sir, I’m edited already. Link is https://www.dropbox.com/sh/zs7yuhgia8a1xjx/AADRJx-nChlme8MgSzO6TZ6oa?dl=0