Pythagorean Theorem Calculator
Enter any two sides of a right triangle and we’ll solve the third using a² + b² = c². Ideal for homework checks, DIY projects, and engineering estimates.
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Triangle Results
Values rounded to two decimals.
Understanding a² + b² = c²
The Pythagorean theorem states that the square of the hypotenuse equals the sum of the squares of the legs in a right triangle. It’s a staple in geometry, trigonometry, construction, physics, and countless DIY tasks.
a² + b² = c²
a = √(c² – b²)
b = √(c² – a²)
c = √(a² + b²)
quick sanity checks
a=3, b=4 → c=5. Classic classroom example.
a=5, b=12 → c=13. Great for carpentry framing.
a=8, b=15 → c=17. Useful for layout work.
Where You’ll Use It
Construction
Check squareness, lay out stairs, or convert diagonal spans when planning beams.
Navigation & Mapping
Calculate shortest distances or resolve horizontal/vertical components of a route.
STEM Classes
Verify homework answers, solve coordinate geometry problems, and prep for exams.
Frequently Asked Questions
You must provide at least two side lengths, and one must be the hypotenuse if you’re missing both legs.
If the hypotenuse isn’t the largest value, the triangle isn’t right. Double-check entries and units.
Yes—enter decimals or whole numbers. We round results to two decimal places for readability.