Hello,

Some guy at my design office managed to make a part that I don't understand.

It's just a plate. Made from a rectangle sketch. Nothing fancy.

(See how the origin is not on the planes intersection?)

But, even if the rectangle is well constraint int he sketch with horizontal and vertical mates, after the extrusion, the faces has a 0.02° angle whit the front plane (for example).

After extrusion :

We remade the part with no problem and everything was fine, but I'm a little curious. What could have happened?

It's look like that the issue is from the sketch, not the part. If you make a new sketch, it will behave normally.

(you can find the part attached, SW2017),

cheers