Trigonometric Ratios

Sine (sin) of an angle is the ratio of the length of the opposite side to the length of the hypotenuse.

Cosine (cos) of an angle is the ratio of the length of the adjacent side to the length of the hypotenuse.

Tangent (tan) of an angle is the ratio of the length of the opposite side to the length of the adjacent side.

$$\text{sin} \theta = \frac{\text{opposite}}{\text{hypotenuse}}$$ .

$$\text{cos} \theta = \frac{\text{adjacent}}{\text{hypotenuse}}$$ .

$$\text{tan} \theta = \frac{\text{opposite}}{\text{adjacent}}$$ .

$$\text{cos} y = \frac{18}{12}$$ .

y = an^{-1}(rac{12}{18}).

$$\text{tan} \theta = \frac{\text{sin} \theta}{\text{cos} \theta}$$ .

Cos X = $$\frac{15}{17}$$ .