Sometimes, you might want to expand your workspace's main content area to better view a spreadsheet, image, or table.  You can effectively accomplish this by hiding the Right Panel. 

By clicking on this triangle, you'll be able to hide and reveal the right panel of your workspace.

If you've hidden the right panel, and you would like it to come back, click the triangle again so that all the content in the right panel comes back.

Please keep in mind that this is just a personal preference, and the right panel is still shown by default for your users.  If you are the administrator of a premium workspace, you can set the default state to be hidden.  Click here for more information.