Sine, cosine and tangent are trigonometric ratios. Within a right-angle triangle: ulliSine is the ratio of the length of the opposite side to the length of the hypotenuse;[/li]liCosine is the ratio of the length of the adjacent side to the length of the hypotenuse; and[/li]liTangent is the ratio of the length of the opposite side to the length of the adjacent side.[/li]/ul [b]uSOHCAHTOA[/u]/brow [col]mtaimg/images/topics/5/5-43-1.png[/mtaimg]/colcol(\sin{x} = \dfrac{O}{H}\qquad\cos{x} = \dfrac{A}{H}\qquad\tan{x} = \dfrac{O}{A})[/col]/row

(\sin{x} = \dfrac{O}{H}\qquad\cos{x} = \dfrac{A}{H}\qquad\tan{x} = \dfrac{O}{A})