The Star tool, like the Polygon tool, will create a multisided shape, but this time as a star. While the tool is selected, you can drag out an equal-sided star. Hold down the Shift key if you want the two bottom points to be horizontal. Refer to Figure 6-15.
Figure 6-15. Toolbars’ Star tool and a star on the artboard
Alt/Option or Alt/Option+Shift drag from the center, and this will cause the second inner radius to alter slightly, making the star more pointy. Again, as you drag out the shape, you can use the up and down arrow keys on your keyboard to add more or less points to the star. Refer to Figure 6-16.
Figure 6-16. While dragging out a star, use the arrow keys to add more or less sides
If you need precise settings, then, while the tool is selected, click the artboard and use the dialog box to set Radius 1, Radius 2, and then number of points (3–1000), and click OK to commit the shape. Refer to Figure 6-17.
Figure 6-17. The Star dialog box and a star on the artboard
Note Unlike the Polygon tool, you will not be able to use the live corner widgets directly for the round cornering of the star; I will show you how to do that later. Also, if you need to make the star disproportionate, you can scale it later with the Selection tool which we will review shortly. Stars can add interest, often for children’s designs or added to something sale related when you want specific text to stand out. Refer to Figure 6-18.
Figure 6-18. Children’s artwork and advertisement for a sale are good uses of the Star tool
You can learn more about the basic shapes from this page.
https://helpx.adobe.com/illustrator/how-to/draw-basic-shapes.html