Join lines

Hi Guys

I m totally new with grasshopper. I am trying to join my lines in one geometry so I can calculate the structural analysis for my project. I have 4 separate triangles and I want to make them all one geometry I can do this when I Bake the structure one by one. So im curious if there is a way to Join all the structure in one so I can do my calculations.

Thank you in Advance

Dimi