You can use sogou input method to print squares, triangles, stars and other patterns, as shown below:

1. Switch the input method to sogou input method, and click "Toolbox" on the far right of sogou input method:

2. In the pop-up dialog box, select the "completion symbol" option:

3. Select "Special Symbol" in the pop-up dialog box, select the required symbol, and click Finish to enter.