The Pythagorean theorem
In a right triangle, the square of the hypotenuse (the side opposite the right angle) equals the sum of the squares of the other two sides: a² + b² = c².
How to use the calculator
Fill in two of the three sides and leave the third empty. If you leave c empty, the tool computes c = √(a² + b²). If you leave a or b empty, it computes the missing leg with √(c² − other²).
Where it is used
- Construction and carpentry, to check that corners are square (3-4-5 rule).
- Navigation and distance between two points.
- Screen sizes: the diagonal of a display.
- Geometry and trigonometry at school.
Frequently asked questions
Does it work for any triangle?
Only for right triangles, those with one 90° angle.
What are Pythagorean triples?
Whole-number sets like 3-4-5, 5-12-13 and 8-15-17 that satisfy the theorem.
Which unit should I use?
Any unit, as long as all sides use the same one.