You can change the size of a slide in your PowerPoint presentation through the "Design" menu on the Windows PC, Apple MacOS, ...
Now let us see these steps in detail. On the Selection Pane, hide every placeholder on the first slide. Close the Selection Pane. Go back to the Slide Master tab and click the Background Styles button ...
Results that may be inaccessible to you are currently showing.
Hide inaccessible results