Introduction: In this lesson, three trigonometric ratios (

**sine**,**cosine, and tangent**) will be defined and applied. These involve ratios of the lengths of the sides in a right triangle. In a right triangle, one angle is 90º and the side across from this angle is**called**the hypotenuse.Keeping this in view, what are the 6 trigonometric functions and their definitions?

The 6 Trig Ratios. For any right triangle, there are six trig ratios: Sine (

**sin**),**cosine**(**cos**),**tangent**(**tan**),**cosecant**(csc),**secant**(sec), and**cotangent**(cot). Here are the formulas for these six trig ratios: Given a triangle, you should be able to identify all 6 ratios for all the angles (except the right angle).What is the rule for Sin Cos Tan?

The functions of

**sin**,**cos**and**tan**can be calculated as follows: Sine Function:**sin**(θ) = Opposite / Hypotenuse.**Cosine**Function:**cos**(θ) = Adjacent / Hypotenuse. Tangent Function:**tan**(θ) = Opposite / Adjacent.What is sine and cosine?

**Sine and cosine**— a.k.a.,

**sin**(θ) and cos(θ) — are functions revealing the shape of a right triangle. Looking out from a vertex with angle θ,

**sin**(θ) is the ratio of the opposite side to the hypotenuse , while cos(θ) is the ratio of the adjacent side to the hypotenuse .