How to slice this 3D object in AutoCAD

[Anonymous]

I'm trying to remove everything below the red line, regular old Slice command isn't doing the trick, thanks

@Anonymous, 

john.vellek has edited your subject line for clarity: How to slice this...

[john.vellek]

Hi @Anonymous,

Have you considered making a rectangular solid and subtracting it?

I will take a look at your file but you might consider trying that in the mean time.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous]

I tried that but got an error message, thanks

[Anonymous · Accepted solution]

Have you tried slice with 3 points?

I tried it with the file you attached I could separate the desire part of the object, how ever patience is necessary due to the fact that sides are not perpendicular to each other.

Another way is to extrude a shape similar to the red one you drew and then subtract.