Name

**Trigonometric ratios**
Figure	Sides
	$\text{Let the right triangle } OHA\,$ $O=\text{ side adjacent to angle }\theta\,$ $A=\text{ side opposite to angle }\theta\,$ $H=\text{ hypotenuse}\,$

**Trigonometric ratios**
Name of Ratio	Abbreviation	Explicit Formula	Formula	Memory Aid
$\text{sine of }\theta\,$	$\sin \theta\,$	$\sin \theta=\frac{\text{side opposite to } \theta}{hypotenuse}$	$\sin \theta=\frac{O}{H}$	$\text {SOH}\,$
$\text{cosine of }\theta\,$	$\cos \theta\,$	$\cos \theta=\frac{\text{side adjacent to } \theta}{hypotenuse}$	$\cos \theta=\frac{A}{H}$	$\text {CAH}\,$
$\text{tangent of }\theta\,$	$\tan \theta\,$	$\tan \theta=\frac{\text{side opposite to } \theta}{\text{side adjacent to } \theta}$	$\tan \theta=\frac{O}{A}$	$\text {TOA}\,$
$\text{cotangent of }\theta\,$	$\cot \theta\,$	$\cot \theta=\frac{\text{side adjacent to } \theta}{\text{side opposite to } \theta}$	$\cot \theta=\frac{A}{O}$
$\text{secant of }\theta\,$	$\sec \theta\,$	$\sec\theta=\frac{\text{hypotenuse}}{\text{side adjacent to } \theta}$	$\sec \theta=\frac{H}{A}$
$\text{cosecant of }\theta\,$	$\csc \theta\,$	$\csc \theta=\frac{hypotenuse}{\text{side opposite to } \theta}$	$\csc \theta=\frac{H}{O}$