If you insert a shape in PowerPoint and you want to change it into another different shape without having to delete it or insert another shape into the slide, you can use the Change Shape feature that ...
If you don’t want the same rectangular pictures for your Microsoft PowerPoint slide show, create a custom-shaped picture placeholder and make it available to the presentation via a layout slide.
The Change Shape feature changes your graphic to a different graphic, preserving its formatting and size. Insert an icon into the slide and click the Graphics Format tab. Click the Change Graphic ...