Sine measures the vertical ratio of an angle on the unit circle or the opposite-to-hypotenuse ratio in a right triangle. It is periodic and always stays between -1 and 1.
⚠Choose the correct angle unit before calculating. Degrees and radians give different numeric inputs for the same angle.
How Sine Works
On the unit circle, sine is the y-coordinate of the point at angle θ. In right triangle trigonometry, it connects an acute angle to side lengths.
Right Triangle
sin(θ) = opposite / hypotenuse.
Unit Circle
Sine is the y-coordinate.
Range
The value is always from -1 to 1.
Period
Sine repeats every 360° or 2π.
💡 Example: For 30°, sin(30°)=0.5.
Applications of Sine
Right TrianglesWave MotionPhysicsNavigation
Frequently Asked Questions
What is a sine calculator?▼
It calculates sin(x) for an angle entered in degrees or radians.
What is the sine formula?▼
In a right triangle, sine is opposite side divided by hypotenuse: sin(θ)=opposite/hypotenuse.
How do I use this calculator?▼
Enter an angle, choose degrees or radians, and click Calculate.
What values can sine have?▼
Sine values range from -1 to 1 for all real angles.
Where is sine used?▼
Sine is used in triangles, waves, oscillations, physics, navigation, and signal processing.
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