The golden ratio should not need any introduction to those who have studied math and design in school. Some designers apply these mathematical concepts to come up with more visually appealing works. This infographic from companyfolders.com covers a few golden ratio facts:
Mathematics Definition Posters Full Version from EduGuru on TeachersNotebook.com - (31 pages) - This is a set of 29 (and more to follow) colorful printable A4 posters to "spice up" your mathematics classroom. They cover mathematics definitions that meets common core standards.