Some good websites for geometry cheat sheets include Math-Salamanders.com and Dummies.com. As of 2015, the printable sheets are free to students and the non-printable sheets are available to everyone. .
At Math-Salamanders.com, students can download and print study reference sheets on angles, 2D shapes, 3D shapes and formulas for shapes. This website allows students to customize the print area and fit the information to a sheet size. Some of the sheets feature pictures that show the information, and others are simply lists of the information.
The Dummies.com cheat sheet comes from its "Geometry for Dummies" workbook. This website offers three cheat sheets for geometry, including one on strategies for problem solving, formulas and common geometry symbols.