Get a line on top of the wall surface

Hi everyone,

Iam quite new with Dynamo. And I want to place familys on top of the wall.

i found a point on that wal.
so the next step is creating a line in the middle of the surface…
and than lets say 500 mm from the side a family

i hope I make myself clear

can someone help me with this?

for line you must set start and end points this line.
this task you can to solve with different ways. For example, via vectors.
“lets say 500 mm from the side a family” - 500mm which way (upper, lower, to left, to right, to surface facet, … etc)?

Thanks for the fast replay

I want the middle line of a blue surface

which way? left to right or up to down?

the long line on the right
thats the one I want to get

Thank you

for example via distance