Pythagorean Theorem Calculator
Last updated: November 5, 2026
Solve a right triangle’s hypotenuse, area, perimeter and acute angles from two legs.
Hypotenuse c
—
- Triangle area: —
- Triangle perimeter: —
- Angle opposite a: —
- Angle opposite b: —
On this page
Quick summary: Solve a right triangle’s hypotenuse, area, perimeter and acute angles from two legs.
Read the complete guide
Updated reference sections in this guide are in English.
What this calculator estimates
Solve a right triangle’s hypotenuse, area, perimeter and acute angles from two legs.
How to use it
Enter Right-triangle leg a; Right-triangle leg b. Select Calculate to update the results.
How the calculation works
For a right triangle, the hypotenuse is the square root of a squared plus b squared.
Worked example: starting scenario
| Right-triangle leg a | 3 |
|---|---|
| Right-triangle leg b | 4 |
| Hypotenuse c | 5 |
|---|---|
| Triangle area | 6 |
| Triangle perimeter | 12 |
| Angle opposite a | 36.869898° |
| Angle opposite b | 53.130102° |
Important limitations
The entered sides are assumed to be the perpendicular legs of a right triangle.
The right-angle assumption is essential
The relation c² = a² + b² applies to a right triangle when a and b are the perpendicular legs. Entering legs 5 and 12 gives hypotenuse 13 and area 30. It does not infer a missing side of an arbitrary triangle. Keep both lengths in the same unit; the resulting area uses that unit squared.