Alter an image's properties and you can make a dramatic visual statement in a document or presentation. Skewing alters an image’s orientation and the angles between lines that form the image’s corners. The resulting image appears distorted and has a subtle three-dimensional effect. PowerPoint has no "Skew" button, but you can skew a PowerPoint image in real-time by altering a few 3-D rotation values.
Right-click an image in one of your PowerPoint slides and click “Format Picture.” Click the arrow next to “3-D ROTATION” to expand that section and view a set of text boxes and buttons.
Click the Left or Right button next to X Rotation and note how the image rotates slightly to the left or right. The Left button displays an arrow pointing to the right and the Right button has an arrow that points to the left. Click the Up or Down button next to Y Rotation, and the image rotates vertically around its vertical axis. These buttons also have arrows. Hold your mouse over any button if you’d like to see a button’s name.
Click the Clockwise or Counter-Clockwise button next to Z Rotation if you’d like to rotate the image clockwise or counter-clockwise around its center. Continue clicking buttons until PowerPoint skews the image the way you like.