Triangle Area Calculator (3 Sides)
Result
Triangle Area Calculator (3 Sides) This triangle area calculator finds the area of any triangle when you know the lengths of its three sides (the SSS case). Enter sides a, b, and c and it applies Heron's formula: it first computes the semi-perimeter s = ( — free online calculator.
Formula
- Enter the specified values using consistent units. The calculator applies the displayed formula; input assumptions and units are stated beside each field.
- The main inputs are Side a, Side b, Side c. Enter them in the units and format shown in the calculator.
- Keep comparable quantities in compatible units whenever the formula combines or compares them.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Triangle Area Calculator (3 Sides)
- Side a: 3
- Side b: 4
- Side c: 5
Example inputs: Side a = 3; Side b = 4; Side c = 5. Calculated result: Area (square units): 6.
Sample result: Calculating…
Frequently asked questions
What does the Triangle Area Calculator (3 Sides) calculate?
The side lengths must form a valid triangle.
Which values should I enter?
Enter Side a, Side b, Side c using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: Heron: s=(a+b+c)/2; area=√(s(s−a)(s−b)(s−c)).
Why might my result differ from another source?
Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.