Pythagorean Calculator – Calculate Right Triangle Sides and Hypotenuse
The Pythagorean calculator solves for any unknown side of a right triangle when two others are known. Enter two sides and the calculator solves for the third.
The tool uses the Pythagorean theorem (a² + b² = c²) and shows the calculation step by step. Perfect for math studies, construction, and any situation requiring right triangle calculations.
How Does the Pythagorean Theorem Work in Practice?
The Pythagorean theorem: hypotenuse squared = sum of legs squared (c² = a² + b²). Practical example: if you want to know the diagonal measurement across a 3m wide and 4m tall wall, the hypotenuse is √(3² + 4²) = √(9+16) = √25 = 5m. The classic 3-4-5 triangle is a builder's basic tool for checking right angles.
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Browse all tools →The Pythagorean calculator determines the length of a right triangle's side when the other two sides are known. A useful tool for students, builders, and anyone needing quick geometry calculations.
Enter two sides of a triangle, and the calculator determines the third using the Pythagorean theorem (a² + b² = c²).
- Calculate the hypotenuse (longest side) from two legs.
- Calculate a leg when you know the hypotenuse and one leg.
- Check if a triangle is right-angled with given sides.
The result is mathematically precise – the Pythagorean theorem only applies to right triangles.
- The triangle must be right-angled (one 90° angle) for the theorem to apply.
- In practical construction, the 3-4-5 rule is a quick way to check a right angle.
- The result is theoretical – measurements always include small inaccuracies.
The Pythagorean theorem is a cornerstone of mathematics, widely used in practical applications.
- In construction and renovation, the calculator helps check diagonal measurements.
- Navigation and map-based calculations use the same principle.
- The calculator works in your browser – your data is not stored.