Description
Return circular walking-line tread arc.
Architectural curves, stairs and roof planes can be described by ideal radii, angles, linear slopes and reference heights. Arc length differs from chord length, and a plan diagonal differs from a sloping member’s length. These local geometry terms do not evaluate structural capacity or building requirements.
Return circular walking-line tread arc.
When to use this tool
Use Stair Winder Walking Line Tread Term when checking the stated ideal curve, tread, slope or reference-plane term.
How to use the tool and how it works
- Enter walkingRadius, angleRadians. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read arcTread. Use the output convention below.
Return circular walking-line tread arc. Require walkingRadius > 0 and angleRadians in (0,pi]; arcTread = radius*angle.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| walkingRadius | Walking Radius | Required. Finite number; strictly above 0. |
| angleRadians | Angle in radians on the specified axis/sign convention. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| arcTread | walkingRadius*angleRadians: an arc length, not the chord. | Required. Finite number. |
{
"input": {
"walkingRadius": 1.2,
"angleRadians": 0.5235987755982988
},
"output": {
"arcTread": 0.6283185307179585
}
}Limitations and assumptions
- The angle is in radians; this is arc length, not chord/clear tread depth or a stair-safety/code check.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete spatial design, verified dimensions and qualified professional review for structural, accessibility and construction decisions.
References
Similar or alternative tools
- Stair Winder Inner Tread Gap
Return average inner winder-tread arc and supplied-minimum gap.
- Door Leaf Undercut Area Term Tool
Calculate door leaf undercut area term from explicit caller-supplied inputs.