Example 1

State the tangent ratio, the sine ratio, and the cosine ratio for the acute angle provided in the diagram.


It is often a good idea to begin by labelling the sides of the given triangle as opposite, adjacent, and hypotenuse.

Now, write the ratios.


When you first start working with the three primary trigonometric ratios, it is easy to forget which sides of the triangle are used for each of the ratios. Some mnemonics that may help you remember are provided.

Sine = Opposite ÷ Hypotenuse

Cosine = Adjacent ÷ Hypotenuse

Tangent = Opposite ÷ Adjacent

  • SOH CAH TOA (often pronounced sew-ka-tow-a)

  • Tommy On A Ship Of His Caught A Herring.

  • The Old Army Colonel And His Son Often Hiccup.


Be sure to find a way to remember the three ratios that works for YOU.