How to translate curve in particular plane

Hi all, I want to translate edges of surface in normal direction on the same plane of surface, so that I can use those curves for dimensioning.
By my dynamo file I am able to translate vertical edges but cant translate horizontal edges please help.
I have attached the screenshot of the element’s surface before and after dimensioning and dynamo file for better understanding.

section_view section_view_dim

@Kulkul I want to get normal to the edge of surface in the same plane of surface.
I have searched so many forums and dynamo nodes but didn’t get the answer.Am I missing any basic thing.I have also uploaded the screenshots of dynamo script in above post.

Can you please help me out.

I hope i understood things correctly.

You can try to get the normals this way too.
(BIM4STRUC package)

Thank you so much Marcel for replying to my query.
By the node you have suggested it is giving me the local co-ordinates of element, I want the vector of the edge of the surface, is there any node for that.

Let me explain to you what I am trying to do is, extracting the edges of surface and translating them by certain distance and using the edge geometry as input giving the dimension to the element.
by my script I am able to successfully translate vertical edges with normal to the edge as direction input
but in case of horizontal edges translation of curve is occurring along the length of beam(As shown in the screenshot)…I want to translate it in the plane of surface…Please help me out. If there is any other method for dimensioning please let me know.
Thanking you in advance.