"SOHCAHTOA" is a helpful mnemonic for remembering the definitions of the trigonometric functions sine, cosine, and tangent i.e., sine equals opposite side over hypotenuse, cosine equals adjacent side over hypotenuse, and tangent equals opposite side over adjacent side lengths, sin θ | = | (o p p o s i t e)/(h y p o t e n u s e) cos θ | = | (a d j a c e n t)/(h y p o t e n u s e) tan θ | = | (o p p o s i t e)/(a d j a c e n t).
adjacent side | cosine | hypotenuse | opposite side | sine | tangent | trigonometry