THE NUMBERS, EXPLAINED
How to use this calculator.
Segment area is sector area minus the signed centre triangle. The entered angle selects the segment.
Start with your inputs
Enter radius, angle (degrees). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Radius | 3 |
| Angle (degrees) | 90 |
A worked example
With the example inputs above, segment area is 2.568583. Change the inputs to explore your own scenario.
Putting the example numbers into the formula
Segment area
(3) × (3) ÷ 2 × ((90) × π ÷ 180-sin((90) × π ÷ 180)) = 2.568583
Chord
2 × (3) × sin((90) × π ÷ 360) = 4.242641
| Result | Example answer |
|---|---|
| Segment area | 2.568583 |
| Chord | 4.242641 |
How this is calculated
Segment area
a × a ÷ 2 × (b × π ÷ 180-sin(b × π ÷ 180))
Chord
2 × a × sin(b × π ÷ 360)
Symbols and units
- a
- Radius
- b
- Angle (degrees)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Calculation steps and notation
sin uses an angle in radians. Convert degrees by multiplying by π/180.
π is the circle constant, approximately 3.141592653589793.
Assumptions and limits
Segment area is sector area minus the signed centre triangle. The entered angle selects the segment.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Segment area; Chord. The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Segment area is sector area minus the signed centre triangle. The entered angle selects the segment.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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