3D Solid Volume/Surface Area Calculator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-177

Effect

Computation or source lookup only

Input and validation requirements

The specification does not state torus validity regimes or spindle-torus handling, so inputs with R<r can produce a plausible but geometrically inappropriate result. Extreme sphere radii also overflow the volume in ordinary JavaScript Number arithmetic, and negative cone heights expose an unstated sign convention.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "solid_type": "sphere",
    "radius": 3,
    "length_unit": "m"
  },
  "expected_outputs": {
    "volume": 113.09733552923255,
    "volume_unit": "m^3",
    "surface_area": 113.09733552923255,
    "surface_area_unit": "m^2"
  },
  "working": "V=(4/3)πr³=(4/3)π(3³)=(4/3)π(27)=36π=113.09733552923255 m^3. SA=4πr²=4π(3²)=36π=113.09733552923255 m^2."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json