Right Triangle Calculator — Pythagoras
Solve one unknown side of a right triangle using the Pythagorean relationship. Side c is the hypotenuse; a and b meet at the right angle.
- Runs in your browser
- Nothing is uploaded
- No signup; device limits apply
Numbers stay on your device. Nothing is sent to a server.
How to use this tool
Set exactly one unknown side to zero and enter positive lengths for the other two. A known hypotenuse must exceed the other known side.
Results and examples
For a=3, b=4 and c=0, the calculated hypotenuse is 5. For a=0, b=4 and c=5, the missing leg is 3. The headline always displays c, so read the a or b row when solving for a leg.
Limitations
- The model does not apply to a non-right triangle.
- Angles, perimeter, area, coordinates and a drawing are not produced.
Fields
| Field | Guidance and constraints |
|---|---|
| Side a | Accepted range: 0–1000000000000 · Input step: 0.0001 |
| Side b | Accepted range: 0–1000000000000 · Input step: 0.0001 |
| Hypotenuse c | Accepted range: 0–1000000000000 · Input step: 0.0001 |
Data handling
Processing stays in the current browser tab; the site does not upload tool input for the calculation itself.
Sources
Frequently asked questions
Can I enter all three sides to check them?
No. This form requires exactly one side to be marked unknown with zero.
What if c is shorter than the known leg?
The engine rejects the input because it cannot form the requested right triangle.
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