I'm going to assume you're talking about trigonometry. You can remember them better with TOA CAH SOH. Read them as it is.
TOA : T stands for Tangent, take Opposite divided by Adjacent.
CAH : C stands for Cosine, take Adjacent divided by Hypotenuse.
SOH : S stands for Sine, take Opposite divided by Hypotenuse.
T
hat is how I remember my trigonometry. Btw, I'm assuming you mean trigonometry, as you didn't specify in your question. Hope this helps ;)