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Circle Segment Area Calculator (A = ½r²(θ−sinθ))

Quick answer

This calculator computes the circle segment area: exact formula A = ½r²(θ−sinθ), worked example r = 6 cm, θ = 90° = 1.5708 rad → A = 10.26 cm².

  • Free, instant, any units.

Figures are estimates from this calculator’s standard formula — adjust the inputs in the tool below for your exact number.

How the circle segment area Calculator Works

A = ½·r²·(θ − sin θ)

The calculator applies the exact formula A = ½·r²·(θ − sin θ). Worked example: r = 6 cm, θ = 90° = 1.5708 rad → A = 10.26 cm². Keep every input in one unit system and the result follows in square units (m², ft², cm²); full precision is kept until the final rounding. All side lengths must share one unit or the area comes out scaled wrongly.

  1. 1

    Enter the measurements

    Type the values required by the formula for circle segment area.

  2. 2

    Check the units

    One unit system throughout — cm, m, ft or in.

  3. 3

    Read the result

    The calculator substitutes, evaluates and rounds only at the end.

Use Cases

Floor, plot and panel measurements

School geometry and land surveying

Double-checking material orders and quotes

Tips

  • 1

    Area scales with the square of linear dimensions

  • 2

    1 m² = 10.764 ft² for quick conversion

  • 3

    Sketch and label the shape before entering values

Common Mistakes

  • Unit mix-ups between cm² and m² (factor 10,000)

  • Using a slanted length as a perpendicular height

  • Treating an irregular shape as regular

FAQs