I use SketchUp Make 2017 and often generate curves by plotting points and connecting them with line segments. I would like to install and use Weld to turn them into polylines. Can I do this, and if so, how?
Select the connecting edges > right click on the selection > select Weld Edges in the right click context menu that appears.
Oops, you talked about SketchUp Make. An extention is needed. See @DaveR’s reply below.
So no extention needed (in SketchUp Web versions)
(The SketchUp Web versions don’t enable installing extentions)