How do you create a rectangle with rounded corners?

To create a rectangle with rounded corners in Adobe Illustrator, the appropriate tool to use is the Rounded Rectangle Tool. This tool is specifically designed for drawing rectangles with smooth, rounded corners, allowing you to easily customize the radius of the corners as you create the shape. When you select the Rounded Rectangle Tool, you can click and drag on the canvas to form the shape, and a dialogue box will often appear, letting you specify the width and height as well as the corner radius.

Other tools in the options provided, such as the Rectangle Tool, are used for creating standard rectangles without rounded corners, and while you can achieve a similar effect with the Shape Builder Tool or by editing a regular rectangle, these methods are more manual and less straightforward than using the Rounded Rectangle Tool directly. The Polygon Tool, on the other hand, is intended for creating polygon shapes and does not cater to the need for rounded corners in rectangles. Thus, the Rounded Rectangle Tool stands out as the most efficient and accurate choice for creating rectangles with rounded corners.