This one image shows all six trigonometric functions. Move the point to explore how they are defined.
[list=1] [*] Find several right triangles in this image and use the Pythagorean theorem to find the relationship between: sine and cosine; tangent and secant; cotangent and cosecant. [*] Can you prove this is correct? (Hint: click on show angles and use similar triangles.) [/list]