Sin(30°) = 1/2
Sine — the y-coordinate of the corresponding unit-circle point, or opposite/hypotenuse in a right triangle.
How to derive sin(30°)
Take an equilateral triangle of side 2 and drop an altitude — you get a 30-60-90 triangle with sides 1, √3, 2. The side opposite 30° has length 1, so sin(30°) = opposite/hypotenuse = 1/2.
Unit-circle context
The angle 30° corresponds to π/6 radians and sits Quadrant I on the unit circle.
Other trig values at 30°
Related sin values
Frequently asked
- What is the exact value of sin(30°)?
- The exact value is 1/2. Its decimal approximation is 0.5.
- How do you derive sin(30°)?
- Take an equilateral triangle of side 2 and drop an altitude — you get a 30-60-90 triangle with sides 1, √3, 2. The side opposite 30° has length 1, so sin(30°) = opposite/hypotenuse = 1/2.
- What is 30° in radians?
- 30° equals π/6 radians (multiply degrees by π/180).
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