PowerPoint provides two types of shapes: open and close shapes. Shapes, such as rectangles, circles, etc. are closed shapes. Regular line shapes, such as straight lines, curves, scribbles, etc. are open shapes. Arrowheads can be added only to open shapes. That’s because an arrow needs a pronounced, visible beginning and end.
Learn how to format arrowheads for lines in PowerPoint 2016 for Windows.

