Enter Any Two Values
The calculator will automatically find the missing side
Result:
Pythagorean Theorem Formula
Where:
- a and b are the legs (shorter sides)
- c is the hypotenuse (longest side)
Quick Examples
If a = 3 and b = 4
c = √(3² + 4²) = √25 = 5
If a = 5 and c = 13
b = √(13² - 5²) = √144 = 12
If b = 6 and c = 10
a = √(10² - 6²) = √64 = 8
Calculator Features
Find Any Side
Calculate missing leg (a or b) or hypotenuse (c) with any two known values
Multiple Units
Support for decimal, feet & inches, meters, centimeters - perfect for any project
Step-by-Step
See detailed calculation steps to understand the mathematical process
Instant Results
Get accurate calculations immediately with high precision decimals
Related Calculators
Learn More About the Pythagorean Theorem
What is the Pythagorean Theorem?
The Pythagorean theorem is a fundamental principle in geometry discovered by the ancient Greek mathematician Pythagoras. It states that in a right triangle, the square of the hypotenuse (the longest side) is equal to the sum of squares of the other two sides. The formula is expressed as a² + b² = c², where 'c' represents the hypotenuse and 'a' and 'b' represent the legs of the triangle.
This theorem is widely used in mathematics, engineering, construction, navigation, and many other fields where precise distance and angle calculations are required.
How to Use This Pythagorean Calculator
Using our Pythagorean Theorem Calculator is straightforward. We've designed it to be intuitive for everyone, from students to professionals.
- Choose your unit system: Select from decimal numbers, feet & inches, inches, meters, or centimeters
- Enter any two side lengths: Provide the lengths for any two sides of your right triangle (e.g., sides 'a' and 'b', or 'a' and 'c').
- Click "Calculate": The tool will instantly solve for the unknown side.
- Review the solution: You'll get the final answer along with a detailed, step-by-step breakdown of the calculation, making it easy to understand the process.
Common Applications & Use Cases
The pythagorean theorem calculator is essential for:
- Construction & Building: Quickly calculate diagonal measurements to ensure corners are square, or determine the length of rafters and braces. Our feet & inches mode is perfect for these tasks.
- Education & Learning: An invaluable tool for students tackling geometry homework. The step-by-step solutions help reinforce mathematical concepts.
- Engineering & Design: Used for structural analysis, mechanical design, and creating precise technical drawings.
- Navigation & Mapping: Forms the basis for calculating the shortest distance between two points in coordinate geometry.
- DIY & Home Projects: Ideal for planning layouts, building furniture, or any project that requires perfect right angles.
Calculator Features & Benefits
Why choose our pythagorean calculator:
- Multiple Unit Support: Works with feet, inches, meters, centimeters, and more
- Feet & Inches Mode: Perfect for construction professionals using imperial measurements
- Step-by-Step Solutions: Learn the mathematical process behind each calculation
- High Precision: Accurate results with decimal precision for professional use
- Mobile Friendly: Works perfectly on phones, tablets, and desktop computers
- Free to Use: No registration, no downloads, completely free online tool
Understanding Right Triangles
A right triangle is a triangle with one 90-degree angle. The pythagorean theorem only applies to right triangles and helps you:
- Find the hypotenuse (c): When you know both legs (a and b)
- Find a missing leg (a or b): When you know the hypotenuse and one leg
- Verify triangle validity: Check if three sides form a valid right triangle
Common right triangle examples include the 3-4-5 triangle, 5-12-13 triangle, and 8-15-17 triangle. These are called Pythagorean triples because they result in whole number solutions.
Historical Background
While named after Pythagoras (c. 570-495 BC), the theorem was known to ancient civilizations including the Babylonians and Egyptians centuries before Pythagoras. The theorem represents one of humanity's earliest mathematical discoveries and remains one of the most important geometric principles.
The theorem has hundreds of different proofs, making it one of the most proven theorems in mathematics. From simple geometric demonstrations to complex algebraic proofs, the pythagorean theorem continues to be a cornerstone of mathematical education worldwide.