Pythagorean Theorem Calculator

Calculate the missing side of a right triangle using the Pythagorean theorem (a² + b² = c²) with step-by-step solutions.

Calculator

Select which side to find and enter the known values to calculate the missing side using the Pythagorean theorem.

Complete User Guide

What is the Pythagorean Theorem?

The Pythagorean theorem states that in a right triangle, the square of the hypotenuse (c) equals the sum of squares of the other two sides (a and b).

a² + b² = c²

Calculation Types

  • Find Hypotenuse (c): c = √(a² + b²)
  • Find Side a: a = √(c² - b²)
  • Find Side b: b = √(c² - a²)

Key Points

  • The theorem only applies to right triangles (triangles with a 90° angle)
  • The hypotenuse (c) is always the longest side
  • The hypotenuse is opposite the right angle
  • Sides a and b are the legs of the right triangle

Examples

Example 1: Find Hypotenuse

Given: a = 3, b = 4

Calculate: c = √(3² + 4²) = √(9 + 16) = √25

Result: c = 5

Example 2: Find Side

Given: b = 4, c = 5

Calculate: a = √(5² - 4²) = √(25 - 16) = √9

Result: a = 3

📤 Share This Tool