What is the Pythagorean Theorem Calculator?
An online math tool on LeCalculators that solves pythagorean theorem calculator problems with clear numeric results for study and everyday use.
Pythagorean Theorem Calculator
Enter any two of legs a, b and hypotenuse c to solve for the unknown side of a right triangle.
Enter two known sides
Leave the unknown side blank. Provide exactly two of a, b, and c.
About this calculator
How to use Pythagorean Theorem Calculator, plus the formulas and logic behind the results.
Tool description
Uses the Pythagorean theorem for right triangles: the square of the hypotenuse equals the sum of the squares of the legs.
How to use
- Review the input fields and choose degrees or radians when asked.
- Enter the known values using consistent units.
- Select Calculate to view results.
- Adjust inputs and recalculate as needed.
Formulas & reference
a² + b² = c²a = √(c² − b²)b = √(c² − a²)c = √(a² + b²)
Trig tips
- Confirm angle mode (degrees vs radians) before evaluating sin, cos, tan.
- Right-triangle tools assume a 90° angle between legs a and b.
- Triangle inequality: each side must be shorter than the sum of the other two.
Calculation logic
Counts how many of a, b, c are provided. With two legs, computes hypotenuse. With one leg and hypotenuse, computes the other leg if c is larger than the known leg.
Educational calculator. Floating-point rounding may differ slightly from textbook answers.
Pythagorean Theorem Calculator FAQ
Common questions about this calculator and how to use the results.
Do I use degrees or radians?
Many trig tools include an angle mode selector. Match the mode to how your angle is written—degrees (°) or radians.
Why is my answer undefined or invalid?
Trig functions have domain limits (for example arcsin needs −1…1). Triangle tools also reject sides that violate the triangle inequality.
How precise are the results?
Results use floating-point math and are rounded for display with mathFormat. Tiny rounding differences vs hand calculation are normal.
Is this calculator free?
Yes. LeCalculators trigonometry tools are free to use in your browser with guides and FAQs on each page.
Can I use this for homework?
Yes—use it to check work. Always show your own steps when your teacher requires a written solution.