You can find any tool by the Menu Structure HERE: https://turbocaddoc.atlassian.net/wiki/display/TC20UG/Menu+Structure
You can find the menu location of any tool by name HERE: https://turbocaddoc.atlassian.net/wiki/display/TC20UG/Tools+Mapped+to+Menus
Breaking (Opening) Closed Objects
Breaks a closed object (polygon, closed polyline, rectangle, closed curve, etc.), turning it into a polyline.
- Use the Edit Tool on the closed object you want to break.
- Right-click on the node at which you want the break, and select Break from the local menu.
- The object is now an open polyline, with two end nodes at the node where you broke the object.