Step 1 Decide which two sides we are using - one we are trying to find and one we already know – out of Opposite, Adjacent and Hypotenuse.Step 2 Use SOHCAHTOA to decide which one of Sine, Cosine or Tangent to use in this question.Step 3 For Sine write down Opposite/Hypotenuse, for Cosine write down Adjacent/Hypotenuse or for Tangent write down Opposite/Adjacent. One of the values is the unknown length.Step 4 Solve using your calculator and your skills with Algebra