How to calculate pythagorean
c = √(a² + b²) a = √(c² − b²)
Worked example. Hypotenuse c: 5.
Example inputs — Solve for: Hypotenuse (c); Side a: 3; Side b: 4; Hypotenuse c: 5. Starting values are illustrative.
From George Guju, founder of Calculyn · Educational calculator guidance, not professional advice.
How it works
In a right triangle, the square of the hypotenuse (the longest side, opposite the right angle) equals the sum of the squares of the other two sides.
Assumptions & limitations
- Results are rounded for display.
Formula and assumptions reviewed October 2026 by the Calculyn team. How we build our calculators
Frequently asked questions
Does this work for any triangle?
Only right triangles (one 90° angle).