Right-Angle Layout Helper (Pythagorean + Diagonal Check)
Compute a theoretical diagonal from side lengths or 3-4-5, then judge measured differences against tolerance.
Automatically suggests practical 3-4-5 marking lengths for field layout work.
Enter Conditions
Set unit, basis method, tolerance, and measured values. The result panel updates instantly.
Review Reference and Judgement
See reference diagonal, recommended 3-4-5 markings, and per-measurement OK/NG in one screen.
How To Use
- Select the unit (mm/in) at the top.
- Choose either side-length input or 3-4-5 input, then enter values.
- Enter tolerance, optionally using quick chips.
- Enter measured diagonals and check difference + status for each row.
- Copy recommended 3k/4k/5k values or the judgement table when needed.
FAQ
What changes when I swap side A and side B?
Reference diagonal d stays the same, but the recommended 3-4-5 assignment (which side gets 3k or 4k) can change for easier marking.
What if tolerance is empty?
Differences are still calculated, but status is shown as “—”. Tolerance is required for OK/NG judgement.
What happens if pasted input contains text?
Only valid numeric tokens are imported. Invalid tokens are skipped and reported.
Is a larger 3-4-5 setup better?
Generally yes. Larger triangles are less sensitive to relative measurement error, so the tool recommends the largest practical scale.
Can I use fractions in inch mode?
Yes. Simple fractions like 1/16 are accepted in quick chips and paste input, then converted internally to decimals.
Notes
- This tool performs geometric calculation and difference judgement only. It does not verify code compliance or structural safety.
- Always measure from the same reference points (nail/mark/corner). Point drift increases error before calculation even matters.
- Measure multiple times and review spread. If spread is large, check measurement method first (tension, alignment, hook contact).