The hypotenuse comes directly from the Pythagorean theorem.

Both input sides must be positive because they are triangle edge lengths.

Enter the two perpendicular sides of a right triangle and read the diagonal length.

1. Enter leg a.
2. Enter leg b.
3. Read the hypotenuse from the result card.

For legs 3 and 4, the hypotenuse is 5.

That is the classic 3-4-5 right triangle.

Negative and blank inputs are rejected before the square root is evaluated.

The result is live, so changing either leg updates the hypotenuse immediately.