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    Sin 30 Degrees

    Sin, Cos, Tan, Cot of an Angle
    Function
    Angle (°)

    What is sin 30°?

    Answer

    sin 30° =
    1/2 = 0.5

    Angle in radians: 30° = π/6. The point of the angle is in quadrant I, where sine is positive.

    P(cos 30°, sin 30°) = (√3/2, 1/2)

    Half of an equilateral triangle with side 1: the hypotenuse is 1 and the leg opposite 30° is 1/2.

    sin 30° = 1/2

    xyOP

    P(cos 30°, sin 30°) ≈ (0.8660, 0.5)

    Highlighted: the projection on the y-axis — sine, y = 0.5.

    All four functions of 30°
    FunctionExact valueDecimal
    sin 30°1/20.5
    cos 30°√3/2≈ 0.8660
    tan 30°√3/3≈ 0.5774
    cot 30°√3≈ 1.7321

    See Also

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    https://calculat.io/en/number/trigonometry/sin--30Copy
    <a href="https://calculat.io/en/number/trigonometry/sin--30">Sin 30 Degrees: Sine of 30° on the Unit Circle - Calculatio</a>Copy
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    Sin 30 Degrees: Sine of 30° on the Unit Circle. sin 30° = 1/2 = 0.5. The sine is the y-coordinate of the point at 30° on the unit circle.
    https://calculat.io/en/number/trigonometry/sin--30/generated.jpgCopy

    Sine of nearby angles

    Anglesin
    27°≈ 0.4540
    28°≈ 0.4695
    29°≈ 0.4848
    30°1/2
    31°≈ 0.5150
    32°≈ 0.5299
    33°≈ 0.5446
    Recalculate with different values ↑

    FAQ

    What is sin 30°?

    sin 30° = 1/2 = 0.5

    How to remember sin 30°, sin 45° and sin 60°?

    Write them as √1/2, √2/2, √3/2: sin 30° = 1/2, sin 45° = √2/2, sin 60° = √3/2. Cosines are the same numbers in reverse order: cos 30° = √3/2, cos 45° = √2/2, cos 60° = 1/2; tan = sin / cos and cot = cos / sin. Here: sin 30° = 1/2 = 0.5.

    Why does a calculator show −0.9880 for sin 30?

    The calculator is in radian mode (RAD): it takes sin 30 as the sine of 30 radians, sin 30 rad ≈ −0.9880. Switch it to degrees (DEG): sin 30° = 1/2 = 0.5. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

    See Also