Note: Undeleting the teacher will not automatically undelete any classes associated to that teacher. Classes will need to be undeleted as well. View Related tutorial..
Within Admin Mode, select the "More" tab from the Admin home page and click on Audit Log.
Select the deleted teacher to be restored by checking the box before his or her name.
Choose "Undelete" from the toolbar.
The undeleted teacher will now show as "Restored" in the audit log.