need help with the slab problem

[correctroom90]

helping out my sister here. she wants to add a room in her home and when the concrete's poured, it seems like it's not.. square? i did some measurements
and found that one side is shorter than the other for about 6-8 inches. then i did the 345 test, other corners were different by 1-5 inches. Not sure wht's going on. is this even possible?

 

[Tulip221]

nothing personal, but this sounds like the slab wasn't properly sqared in the first place. Since the damage is already done I'd build around it and make sure to create an even layer

 

[TonyPiyas]

I had the same issue, and calibrating with a credit card worked better for me than entering my screen size. After that, I started using the digital ruler because it stayed accurate as long as I didn’t mess with the browser zoom. Just make sure JavaScript is on, or the calibration won’t stick.

 

[Thanos]

Yes, that much variance usually points to formwork error or layout drift before the concrete was poured.