Quick answer
- 36 in rise and 48 in run: diagonal is exactly 60 in.
- 12 ft rise and 16 ft run: diagonal is exactly 20 ft.
- 96 in rise and 128 in run: diagonal is 160 in, or 13'-4".
App Screenshot
Right-angle layout screen
This screenshot comes from the small slab layout recording tied to this right-angle guide.
Field Use
Where square checks matter most
Right-angle verification shows up before concrete, before framing, and before finish work when a room has to stay square. It is one of the simplest calculations to verify, but one of the easiest to mis-enter if the crew mixes feet and inches.
- Use it on slab and foundation layout before forms are locked in.
- Use it on interior partitions before drywall covers the mistake.
- Use it when pitch ratio and diagonal both matter from the same pair of inputs.
Worked Examples
Three square-layout checks
These examples follow the Right Angle tool exactly, including its inch-based inputs.
Example 1
Small slab layout
Inputs: 36 in rise and 48 in run.
This is the classic 3-4-5 scaled layout check. Construction Pro returns an exact diagonal of 60 in, which confirms a square corner and gives the crew a clean number to tape quickly.
Example 2
Addition foundation layout
Inputs: 12 ft rise and 16 ft run.
Enter these values as 144 in and 192 in in the app. The diagonal lands at 20 ft, which is the scaled-up version of the same 3-4-5 relationship and a dependable foundation check before concrete work starts.
Example 3
Interior wall layout check
Inputs: 96 in rise and 128 in run.
For room layout or wall framing, the diagonal works out to 160 in, or 13'-4". That makes it easier to confirm the room is square before backing material hides the problem.
Common mistakes
What ruins a square check
- Entering feet directly when the tool expects inches.
- Swapping measurements inconsistently across corners during layout.
- Using a diagonal target without checking that the tape points match the actual corner lines.
Related guides
FAQ
Right-angle questions
Why does the app ask for inches instead of feet?
The Right Angle tool is designed around the same unit system used for many field layout checks, which keeps small values easy to compare.
Do rise and run have to be in the same unit?
Yes. They must use the same unit or the diagonal result will be wrong.
Can I use this for roof pitch too?
Yes. The tool also reports a pitch ratio and pitch angle from the same rise and run inputs.
Soft App CTA
Keep square checks close to the layout stakes
Construction Pro turns rise and run into a diagonal fast, which is exactly what you want when the layout crew is waiting.