How to use the Pythagorean Theorem Calculator
The Pythagorean theorem calculator finds a missing side of a right triangle.
Open the Pythagorean Theorem Calculator →
What you need to enter
- Solve for
- Side a
- Side b
- Hypotenuse c
The formula
a² + b² = c², where c is the hypotenuse.
Worked example
Using the default values in the calculator:
- Solve for: Hypotenuse c
- Side a: 3
- Side b: 4
- Hypotenuse c: 5
| Hypotenuse c | 5 |
| Area | 6 |
| Perimeter | 12 |
| Angle A | 36.8699° |
| Angle B | 53.1301° |
Tips for better results
- The hypotenuse is always the longest side.
- Check that squares make sense.
Common mistakes to avoid
- Using it for non-right triangles.
- Taking square roots of negative numbers.