The Line Spacing dialog box opens. Click the up or down arrow to change the amount of spacing between lines of text, and then click OK .
PowerPoint adjusts the line spacing.
Line spacing refers to the amount of space between lines of text in a paragraph. You can control line spacing in PowerPoint using the Line Spacing dialog box.
Other Line-Spacing Options
The Line Spacing dialog box also offers controls for setting the amount of spacing before and after paragraphs. Generally, however, if you use too many paragraphs on a slide, it's more difficult for the audience to read the material.