When do I use Sin, Cos or Tan?

You use these functions when you either have a length and an angle and you are looking for a length or when you have two lengths and are looking for an angle. There is a simple way to remember which one to use. SOH CAH TOA is the most common way of remembering. Take the triangle provided and note what each length is in relation to the angle (opposite, adjacent and hypotenuse). Now underline the letters that correspond to the information you have. The one with both of the letters underlined is the one to use.