Joining Segmented Lines

Hello, is there a way to join segmented lines into one single line? This would make it easier to divide for my project. I know that layout has this feature. Thanks

Weld was the first such plugin to make a polyline.

Bezierspline also will let you select your segments > r-click and choose BZ - convert to…

Note, you should read the tutorial that comes with Bezierspline to fully utilize this useful extension.

For colinear edges in SketchUp, draw a new edge from the endpoint where they meet, and then erase it. The edges will get joined.