The theorem states that the square of the hypotenuse equals the sum of the squares of the two legs.

This calculator can solve for any missing side or verify a full triple.

Enter any two sides to solve for the third, or enter all three to verify a right triangle.

1. Enter two or three side lengths.
2. Read the solved side or the verification result.
3. Use the formula card to confirm the math.

With legs 3 and 4, the missing side is 5.

With 3, 4, and 5 entered, the calculator verifies the triangle as valid.

Blank and malformed inputs are rejected explicitly, and the verification check uses a small tolerance for floating-point arithmetic.

If the three sides are all present but do not satisfy the theorem, the calculator says so instead of inventing a result.