How do you do sine and cosine?

Answer 1

It would help if I knew a little more information about what you're looking for, in order to better answer your question, but here are the basics.

For a right triangle, given one of the angles that is not the 90° angle:

• sine is the ratio of the length of the side opposite the angle divided by the length of the hypotenuse.
• cosine is the ratio of the length of the side adjacent to the angle divided by the length of the hypotenuse.

One way to remember this is: Sine, Cosine, Tangent; then think of Old Harry Always Has Old Apples. Sine = O/H, Cosine = A/H, and Tangent = O/A,

where O is the Opposite side, A is the Adjacent side, and H = Hypotenuse.

Another one that somebody taught me is: Oh Heck Another Hour Of Algebra. Pick whatever helps you to remember.