Pythagorean Theorem Calculator

📐 Triangle Calculator

a² + b² = c²

Where c is the hypotenuse (longest side)

Side A

Side B

1

Select what to find - Choose whether you need to find the hypotenuse (c) or one of the shorter sides

2

Enter known sides - Input the two sides you know

3

Click Calculate - Get the missing side plus triangle area and perimeter

What is the Pythagorean Theorem?

In a right triangle, the square of the hypotenuse (the side opposite the right angle) equals the sum of the squares of the other two sides.

Finding the Hypotenuse

c = √(a² + b²)
Square both sides, add them, then take the square root.

Finding a Missing Side

a = √(c² - b²) or b = √(c² - a²)
Square the hypotenuse, subtract the other side squared, then take the square root.

Area = (a × b) / 2

For right triangles, area = half the product of the two shorter sides