Polyline ^

A single object that is composed of line and arc segments

Home tab > Draw panel > Polyline

Width Option

Arc and Width

Arc Direction

Poly Edit - PEdit

Double-click on the polyline to edit

Select Open

The last segment open

Draw a line to connect the opening

Double-click on the polyline, select Join.

Cross-select the line and polyline, then press [Enter] key.

Convert Polyline to Line & Arc

Convert Line & Arc to Polyline