Solve right triangle problems using Pythagoras theorem with detailed step-by-step solutions
Enter two sides of a right triangle to find the third side
Pythagoras Theorem
In a right-angled triangle, the square of the hypotenuse equals the sum of squares of the other two sides.
Mathematical Expression
a² + b² = c²
Where c is the hypotenuse
a² + b² = c²
Where: a and b are the legs, c is the hypotenuse of a right-angled triangle
Our Pythagoras Theorem Calculator helps you solve right triangle problems by calculating the missing side using the famous Pythagorean theorem. This essential geometry tool provides step-by-step solutions for educational and practical applications.
The Pythagorean theorem states that in a right-angled triangle, the square of the hypotenuse (the side opposite the right angle) equals the sum of the squares of the other two sides. This fundamental relationship is expressed as:
a² + b² = c²
Where a and b are the legs (shorter sides) and c is the hypotenuse (longest side).
Example 1: Find hypotenuse (3-4-5 triangle)
Given: a = 3, b = 4, find c
c = √(3² + 4²) = √(9 + 16) = √25 = 5
👉 This is the famous 3-4-5 right triangle ✓
Example 2: Find missing leg
Given: a = 5, c = 13, find b
b = √(13² - 5²) = √(169 - 25) = √144 = 12
👉 This forms a 5-12-13 right triangle ✓
Q1. What is a right-angled triangle?
A: A right-angled triangle has one angle that measures exactly 90 degrees. The side opposite this angle is called the hypotenuse.
Q2. Can Pythagoras theorem be used for non-right triangles?
A: No, Pythagoras theorem only applies to right-angled triangles. For other triangles, use the law of cosines.
Q3. What are some common Pythagorean triples?
A: Common triples include (3,4,5), (5,12,13), (7,24,25), and (8,15,17). These are sets of integers that satisfy a² + b² = c².
Q4. How accurate are the calculations?
A: Our calculator provides results with 4 decimal places of precision, suitable for most practical applications.
Q5. What if I enter invalid values?
A: The calculator will prompt you to provide exactly two side lengths. Make sure to leave one field empty for the side you want to calculate.
For further understanding and validation of the formulas used above, we recommend exploring these authoritative resources: