목공 3-4-5 법칙 직각 계산기
Verify true 90° framing layouts for decks, sheds, tile grids, and wall plates with tape-measure fractional inches (1/16") or metric millimeters. Need to solve abstract right triangles, angles, or exact surds? Use our main Pythagoras equation solver.
목공 3-4-5 법칙 직각 계산기
3² + 4² = 5² · Tolerance: ±1/16 in
현장용 3-4-5 배수 조견표
| Scale | Run (A) | Rise (B) | Diagonal (d) |
|---|---|---|---|
| 1× | 3 in | 4 in | 5 in |
| 2× | 6 in | 8 in | 10 in |
| 3× | 9 in | 12 in | 15 in |
| 4× | 12 in | 16 in | 20 in |
| 5× | 15 in | 20 in | 25 in |
현장용 3-4-5 배수 조견표
| Scale (k×) | 밑변 / 변 A (3k) | 높이 / 변 B (4k) | Diagonal (5k) | Typical Trade Use |
|---|---|---|---|---|
| 1× | 3 ft / m | 4 ft / m | 5 ft / m | Cabinets, tile corners, small frames |
| 2× | 6 ft / m | 8 ft / m | 10 ft / m | Interior wall plates & doorway framing |
| 3× | 9 ft / m | 12 ft / m | 15 ft / m | Medium decks, patios, concrete forms |
| 4× | 12 ft / m | 16 ft / m | 20 ft / m | Full deck bays, garages & outbuildings |
| 5× | 15 ft / m | 20 ft / m | 25 ft / m | Large foundations & timber pole barns |
Step-by-Step Framing Verification Guide
Any integer triple obeying a² + b² = c² locks the angle opposite c at an exact 90.00° by the converse of the Pythagorean theorem. Because 3² + 4² = 9 + 16 = 25 = 5², scaling by any constant factor guarantees squareness regardless of units.
When checking an entire four-sided deck frame or stud wall, compute the full diagonal from your real dimensions above. Measure both opposite corner-to-corner diagonals—even if opposite sides match, a parallelogram only becomes a rectangle when both diagonals equal √(a² + b²).