Home » Tip of The Day » Quickly Increases The Number of Sides in The Polygon ToolQuickly Increases The Number of Sides in The Polygon Tool November 23, 2016. Posted in: Tip Of The Day. When using the Polygon tool, press [ or ] to decrease or increase the number of sides by one. Holding the Shift key will increase or decrease the number of sides by 10. « Previous Photoshop Tip: | Next Photoshop Tip: » Sign-up for the PTC Newsletter so that you'll never miss a tutorial!. Your Email Address: