Right click the line - entity info - then change segments to smooth out the curve
I think SU defaults at 24 segments, but if you increase this it will smooth out 
Oops, your profile's looking a bit empty! To help us tailor your experience, please fill in key details like your SketchUp version, skill level, operating system, and more. Update and save your info on your profile page today!
🔌 Easy Offset | Offset selected faces in SketchUp in positive and negative offsets. Download
S
Offline
Posts
-
RE: Improvement for AutoCAD (.dwg) curve lines (ellipse) import