Pythagorean theorem calculator
Calculate the hypotenuse or a leg of a right triangle using the Pythagorean theorem.
Hypotenuse c
5
a² + b² = c²
Calculations are based on Estonia's tax rates in force for 2026. Results are informational.
Last updated: 2026-06-03
What is the Pythagorean theorem?
In a right triangle the square of the hypotenuse equals the sum of the squares of the legs: a² + b² = c². The hypotenuse c = √(a² + b²); a leg b = √(c² − a²).
How it is calculated
Formula
in a right triangle a² + b² = c². Hypotenuse c = √(a² + b²); leg b = √(c² − a²).
Example
Legs 3 and 4 → hypotenuse √(9 + 16) = 5.
Frequently asked questions
What is the Pythagorean theorem?+
In a right triangle a² + b² = c², where c is the hypotenuse and a, b are the legs.
How do I find a leg?+
If you know the hypotenuse c and one leg a, the other leg is √(c² − a²).