Pythagorean Theorem Calculator

Leave exactly one of a, b, or c blank. The calculator solves the missing side, validates the hypotenuse relationship, and shows a labeled right-triangle diagram plus supporting geometry.

Leg a

Leg b

Hypotenuse c

Leave exactly one side blank. c is always the hypotenuse.

Pythagorean check

a² + b² = c²

Side lengths3 · 4 · 5

Acute angles36.87° · 53.13°

ClassificationRight triangle

Use consistent measurements and valid geometric assumptions

Keep linear inputs in a consistent unit, verify that side lengths or coordinate points can form the stated shape, and treat sketches as explanatory unless explicitly marked to scale. Coordinate formulas can become unstable for nearly degenerate shapes, so invalid or nearly collinear inputs are rejected rather than silently returning misleading values.

How to use the Pythagorean Theorem Calculator

Enter any two positive side lengths of a right triangle and leave exactly one side blank. Side c must be the hypotenuse.

What the result includes

The tool solves the missing side, shows a labeled right-triangle diagram, verifies a²+b²=c² numerically, and calculates area, perimeter, and the two acute angles.

Limits

This theorem applies only to right triangles. If c is known, it must be longer than either leg.