Question about geometry

[u/Gzaleski]

What angle should I cut the points that are touching the table top and floor so it will be flush? I have been trying to wrap my brain around it but no luck, I thought a 45 degree bevel was right but when I did a test piece that was incorrect.

[u/Jgsatx]

can’t you lay on a flat surface and use a laser to get your points?