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Math · Calculator

Pythagorean Theorem Calculator

Solve for a missing leg or hypotenuse in a right triangle when the other two sides are known.

Missing side c

5

Results are deterministic client-side calculations. Review assumptions and units before using a result in school, business, construction, or technical work.

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How to use this calculator

Solve for a missing leg or hypotenuse in a right triangle when the other two sides are known.

How the calculation works

  • Enter two side lengths and leave one side blank.
  • The calculator applies a² + b² = c².
  • The missing side is solved with a square root.

Formula

a² + b² = c².

Example

With legs 3 and 4, the hypotenuse is 5.

Understanding your result

Use the output as a practical starting point, then review it before using it in an important workflow.

Assumptions and limitations

  • c is the hypotenuse and must be the longest side.
  • Leave exactly one side blank.

Frequently asked questions

Does this require an account?

No. The core tool works without creating a Tool2Do account.

Is my input included in share links or analytics?

No. Tool2Do share actions use the tool page URL and safe metadata, not private values or uploaded files.

Pythagorean Theorem Calculator | Tool2Do