Pythagorean Theorem Calculator

Calculate the missing side of a right triangle using the Pythagorean theorem.

Hypotenuse (c)
5.0000
a²
9.00
b²
16.00
Share results:

What is Pythagorean Theorem Calculator?

A Pythagorean theorem calculator finds the missing side of a right triangle when two sides are known.

It is one of the most used formulas in construction, navigation, and geometry.

How does the Pythagorean Theorem Calculator work?

a² + b² = c²

The calculator solves for the hypotenuse or either leg.

It also shows the triangle's area and perimeter.

How to use the Pythagorean Theorem Calculator?

  1. Enter any two sides of the right triangle.
  2. The calculator shows the missing side, area, and perimeter.

Example

Try the calculator with your own numbers

  1. Enter your values in the input fields above.
  2. Adjust the values to match your situation.
  3. The result updates instantly as you change the inputs.
Your result appears instantly — no manual calculation needed.

Benefits of using the Pythagorean Theorem Calculator

  • Measure diagonals and heights.
  • Solve geometry problems.
  • Check right-angle constructions.

Who should use the Pythagorean Theorem Calculator?

  • Students practising problems and verifying homework answers.
  • Teachers preparing examples and checking student work.
  • Engineers and analysts who need quick, reliable calculations.
  • Anyone who wants to double-check manual arithmetic.

Tips for getting the most out of the Pythagorean Theorem Calculator

  • Check your inputs for typos — a single wrong digit changes the result completely.
  • Use the result to verify your manual working, not to replace understanding.
  • Try a simple case first (like 0 or 1) to make sure the output makes sense.

Frequently Asked Questions

What is a Pythagorean triple?

A set of three whole numbers satisfying a² + b² = c², like 3-4-5.

Does the theorem work for all triangles?

No — only for right triangles. Other triangles use the law of cosines.

This calculator turns a tedious calculation into an instant answer, so you can focus on understanding the concept instead of the arithmetic.

Related Calculators