Triangle Calculator accuracy and testing

Formula source

• 1. Calculate the **Semi-Perimeter (s)**: $s = (a + b + c) / 2$ 2. Calculate **Area**: $\sqrt{s(s-a)(s-b)(s-c)}$ This method works for any triangle (scalene, isosceles, or equilateral) as long as the side lengths are valid.

Test cases

Known limitations

• This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
• Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

• All three side lengths are entered in the same unit.
• The calculator uses Heron's formula, so it assumes the three numbers describe side lengths rather than base-height data.
• If the side values are missing or non-positive, the calculator reports invalid input and does not return numeric results.
• If the triangle inequality is not satisfied, the triangle is marked as invalid geometry and numeric results are not returned.

Unit handling

• Side a accepts numeric values.
• Side b accepts numeric values.
• Side c accepts numeric values.

Rounding rules

• Number displays use up to 2 decimal places in the calculator UI.

Version history

Change log