Math
Pythagorean Theorem Calculator
a² + b² = c². Solve any side of a right triangle. Useful for diagonal measurements, framing squareness checks, and stair stringers.
FAQ
The 3-4-5 trick? +
Carpenters use it to check for square corners. Measure 3' on one side, 4' on the other; the diagonal should be exactly 5'. If it isn't, the corner isn't 90°.
Only right triangles? +
Yes. For non-right triangles you need the Law of Cosines.