To add a shadow to an object, click on the object to select it.
Click the Shadow button on the Drawing toolbar and click a shadow style.
PowerPoint applies the shadow.
To make your illustration pop off the slide, you can add shadow effects. Shadows create the illusion of depth by making it appear as though light is shining on the object. You can add shadows to any slide object.
For added control, you can click the Shadow Settings option in the Shadow drop-down list to display the Shadow Settings toolbar. This toolbar has buttons for changing the placement of the shadow as well as the shadow color .
If you do not like the effect of a formatting setting you apply to a selected object, simply click the Undo button on the Standard toolbar to undo your work.