Isosceles Triangle Area Calculator
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Isosceles Triangle Area Calculator — free online calculator.
Formula
Area = base × sqrt(equal side² − (base/2)²) / 2.
- Enter the geometric dimensions indicated below. Dimensions must use compatible units; the output is an area in squared units unless otherwise stated.
- The main inputs are Equal side length, Base length. 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: Isosceles Triangle Area
Inputs
- Equal side length: 5
- Base length: 6
Example inputs: Equal side length = 5; Base length = 6. Calculated result: Area: 12.0000 square units.
Sample result: Calculating…
Frequently asked questions
What does the Isosceles Triangle Area calculate?
The base must be shorter than twice the equal-side length.
Which values should I enter?
Enter Equal side length, Base length using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: Area = base × sqrt(equal side² − (base/2)²) / 2..
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.