Pythagorean Theorem Calculator

Solve the Pythagorean theorem a² + b² = c² — find the hypotenuse, a leg, or check if sides form a right triangle.

Solve for

Leg a

Leg b

Hypotenuse c

Result

Last updated: 2026-08-30

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FAQ

What is the Pythagorean theorem?

In a right triangle, the square of the hypotenuse equals the sum of the squares of the two legs: a² + b² = c².

How do I find a missing leg?

Rearrange to a = √(c² − b²). The hypotenuse must always be longer than the leg you know.

Does the theorem work for any triangle?

No — only right triangles. For other triangles use the law of cosines: c² = a² + b² − 2ab·cos(C).

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