Rigula
Singaporeen-SG

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Locale-aware

SSS and SAS triangle calculatorSG · en-SG

Calculate all sides, all angles, perimeter, and area with strict triangle validation.

Use one consistent side unit; area uses that unit squared.

Ready.

How to use it

Use SSS for three known side lengths or SAS when two sides and the angle between them are known.

  1. Choose SSS or SAS and enter positive side lengths in one consistent unit.
  2. For SAS, enter the included angle strictly between 0° and 180°.
  3. Solve and review all dimensions; the area uses the square of the side unit.

Worked example

Input
SSS: 3, 4, 5
Output
Angles about 36.87°, 53.13°, 90° · perimeter 12 · area 6

The strict triangle inequality rejects sides that collapse to a line.

Method and definitions

  • SSS uses the Law of Cosines for angles and a stable form of Heron's formula for area.
  • SAS uses the Law of Cosines for the third side and ½ab sin(C) for area.

Limits and edge cases

  • SSA, AAS, coordinate, spherical, and right-triangle-only workflows are outside this version.
  • Measurement tolerance and uncertainty are not inferred; all input sides share one unnamed unit.

Privacy

All input and output stays in this tab. Rigula does not upload, store, or include it in a share URL.