**Contents**show

## How is sine defined?

1 : the trigonometric function that for an acute angle is **the ratio between the leg opposite the angle when it is considered part of a right triangle and the hypotenuse**.

## What does sin mean in geometry?

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 .

## How do you find sine in geometry?

In a right triangle, the sine of an angle is **the ratio of the length of the opposite side divided by the length of the hypotenuse**.