Pythagorean Theorem Calculator – Solve Right Triangles, Angles & Sides Instantly

Solve right triangle problems instantly with this free Pythagorean Theorem Calculator. Calculate missing sides, angles, and area using the classic a² + b² = c² formula. Supports reverse calculations, 3D geometry, isosceles triangles, and construction measurements in inches. Whether you're working with algebra, acute angles, or adjacent sides, this tool gives fast, accurate results—perfect for students, engineers, and DIY builders.

Pythagorean Theorem Calculator

Side A (a):

Side B (b):

Hypotenuse (c):

The Pythagorean Theorem

The Pythagorean theorem states that in a right-angled triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. It can be written as:

c² = a² + b²

Where:

• c is the length of the hypotenuse
• a and b are the lengths of the other two sides

How to Use This Calculator

To calculate the missing side of a right-angled triangle:

1. Enter the lengths of any two sides of the triangle in the input fields.
2. Leave the input field for the side you want to calculate empty.
3. Click the "Calculate Missing Side" button.
4. The result will be displayed below the button.