They are displayed horizontally, with slide numbers starting from one, but there are features in PowerPoint that allow the user to change the slide’s size and orientation.

Click the downward-facing arrow below "New Slides" in the Slides group on the Home tab. PowerPoint displays a list of available slide layouts. Click the type of layout you want to use for your new ...

Sometimes a presentation may need to be viewed in vertical or horizontal slides. PowerPoint calls these options Portrait and Landscape, and you can easily change the orientation from within the ...

To change your PowerPoint slideshow orientation from horizontal to portrait, you must access the "Slide Size" feature under the "Design" tab.

Master the ability of changing themes in Google Slides and PowerPoint with simple steps. Make unique presentations and engage your audience.

So, open the PowerPoint slide and insert a shape into the slide. Once you insert a shape in your document, a Shape Format tab will appear on the menu bar with tools to format your shapes.

You can change the size of a slide in your PowerPoint presentation through the "Design" menu on the Windows PC, Apple MacOS, and web-based apps.