How it is calculated
The sum of the squares on the two legs equals the square on the hypotenuse. If a leg is unknown, its square is the hypotenuse squared minus the other leg squared.
c² = a² + b²
Where the numbers come from
- Leg a — Clear the field if you are solving for that leg.
- Leg b
- Hypotenuse c — Leave it empty to find the hypotenuse.
Example
Legs 3 and 4. Hypotenuse √(9 + 16) = 5.
Questions
Which field should I leave empty?
Whichever one you need to find. If all three are filled in and they disagree, the calculator says so.
Does the triangle have to be a right triangle?
Yes. For any triangle, open the area calculator.
Why can't the hypotenuse be shorter than a leg?
Otherwise the value under the root is negative. No such right triangle exists.