Edit menu > Undo or Redo
Toolbar > Undo or Redo
Keyboard > CTRL+Z (Undo) or CTRL+A (Redo)
The Undo command reverses the last operation performed on any selected object(s). Redo reverses the last operation performed by the Undo command.
When you create an object, the Create operation is recorded by the software and displayed next to the activated Undo command in the Edit menu. When you undo the Create operation, the Redo Create operation is displayed next to the activated Redo command in the Edit menu. The Undo and Redo commands in the Edit menu are unavailable when no valid operation was performed or recorded.
Undo and Redo are also available as buttons on the Main toolbar. When you right-click the Undo or Redo button, a History list box opens, listing the last operations performed. One or more of these operations can be highlighted and reversed by the respective Undo or Redo command.