How do I view a complete task and its relevant worksheet as a manager?

Go in to the Task & Worksheet Module from the Administration Bar

Tasks in the list view can be filtered and sorted to enable you to find what you are looking for easily. 

To view an existing task simply press on the relevant task Title which will open the detailed view. 

You will be able to see who the tasks is assigned to, how much progress has been made and the original worksheet. 

To access the completed or partially completed worksheet that has been assigned as part of the task got to 'manage'

If the worksheet has been saved and completed a eye icon  will be present to show that you can view but not alter the fields.