Isosceles Triangle Calculator

units
Enter equal side in units.
units
Enter base in units.
Math

Isosceles Triangle: calculate results from explicit inputs, with a formula and worked example.

Formula

height = √(equal side²−base²/4); area = base × height / 2

Example Calculation

Example inputs
  • Equal side: 5 units
  • Base: 6 units

Equal sides 5 and base 6 give height 4 and area 12.

Frequently asked questions

How do I use this calculator?

Enter equal side, base. The result updates automatically. Use Reset to restore the example values.

What method does it use?

height = √(equal side²−base²/4); area = base × height / 2. Euclidean geometry. Use one consistent length unit; areas and volumes use its square and cube. Degenerate shapes are rejected. Very thin shapes may lose floating-point precision.

Why might a rounded result differ?

The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.

Are my inputs saved online?

No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.

Check the assumptions and units before using this result. Read about calculation methods.