Use as an introduction or recap to lessons on trigonometry. Discuss with students that the different trig functions are based on ratios and show this by comparing similar triangles.

Stuart Anderson, a professor emeritus of mathematics at Texas A&M University–Commerce, told Scientific American, “A lot of the basic trig ‘identities’ are nothing more than Pythagoras ...

Use as an introduction or recap to lessons on trigonometry. Discuss with students that the different trig functions are based on ratios and show this by comparing similar triangles.