Right Triangle Calculator

units
Enter leg a in units.
units
Enter leg b in units.
Math

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

Formula

c = √(a²+b²); A = atan(a/b); B = 90°−A

Example Calculation

Example inputs
  • Leg a: 3 units
  • Leg b: 4 units

Legs 3 and 4 give hypotenuse 5, area 6 and perimeter 12.

Method references

Frequently asked questions

How do I use this calculator?

Enter leg a, leg b. The result updates automatically. Use Reset to restore the example values.

What method does it use?

c = √(a²+b²); A = atan(a/b); B = 90°−A. 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.