Mnemonics in trigonometry

In trigonometry, it is common to use mnemonics to help remember trigonometric identities and the relationships between the various trigonometric functions. The sine, cosine, and tangent ratios in a right triangle can be remembered by representing them as strings of letters, for instance SOH-CAH-TOA in English: Sine = Opposite ÷ Hypotenuse Cosine = Adjacent ÷ Hypotenuse Tangent = Opposite ÷ Adjacent One way to remember the letters is to sound them out phonetically (i.e.

Source: Wikipedia — Mnemonics in trigonometry (CC BY-SA 4.0)