I finally learned how to do sines, cosines, and tangents of triangles. (Seriously, if you found out my age, you might be surprised ) I'm showing this for the younger ones out there.

A sine is the opposite side of the triangle divided by the hypotenuse. S=O/H. If you put this on a function grapher, like the one on Math Is Fun, or the CAS on GeoGebra, it makes a wave pattern.

A cosine is the adjacent side divided by the hypotenuse. C=A/H. If you put this on a function grapher, it also makes a wave pattern.

A tangent is the opposite side divided by the adjacent. T=O/A. On a circle, tangents are lines that touch the circle once, then go off... if you have two, it's like dumplings and chopsticks.

You can remember S=O/H, C=A/H, and T=O/A by thinking SOHCAHTOA. (so-cuh-to-uh)

Since I still can't upload pictures or links, I would appreciate posting a right angle with the corners labeled A, B, and C, the adjacent, hypotenuse, and opposite labeled, adjacent is A and C, opposite B and C, and hypotenuse A and B.