Join - Modify

Joins similar objects to form a single, unbroken object

Home tab > Modify panel expand > Join

Line + Line

Lines only can join collinear (along same path)

Line + Polyline

Polyline only can join without gap

Line + Arc

Line and arc only can join without gap

Polyline + Arc

Polyline and arc only can join without gap

Line + Spline

Line and spline can join without gap

Polyline + Spline

Polyline and spline only can join without gap

Arc + Arc

Arcs only can join within the same circular path (same center and same radius)