Choose whether to find the hypotenuse or one of the other sides of a right-angled triangle, then enter the two lengths you know.
Result
This result is an estimate only. Check with your bank or the relevant authority before making decisions.
How it is calculated
For a right-angled triangle, a² + b² = c², where c is the hypotenuse.
Finding the hypotenuse: c = √(a² + b²)
Finding a leg: leg = √(c² − a²), where c must be larger than a
Results are shown to four decimal places.
Worked example
Legs 3 and 4: hypotenuse = √(9 + 16) = 5.0000
Known leg 5 and hypotenuse 13: other leg = √(169 − 25) = 12.0000
Known leg 13 and hypotenuse 5: error, because the hypotenuse is shorter than the known leg
Why your number may differ
The theorem only applies to right-angled triangles. Make sure both lengths use the same unit, and that you enter the hypotenuse in the correct field when you choose leg mode.
Frequently asked questions
What is the Pythagorean theorem?
For a right-angled triangle, a² + b² = c², where c is the hypotenuse and a and b are the other two sides.
What is the hypotenuse?
The hypotenuse is the longest side of a right-angled triangle, the one opposite the right angle.
Why do I get an error in leg mode?
The hypotenuse must be longer than the known leg. Otherwise no matching right-angled triangle exists.