purpose of the flatten command?

I would like to ask to anyone, viewing in this forum on the purpose of the flatten command . What are the things that we can do when we are to flatten a 3d object. what the use..? I will greatlly appreciate on somone who will reply on this post...thanks in advance....

If you have an item that has been extruded that shouldn't be, you use the FLATTEN command to unextrude it. Or if you have a 3D polyline, flatten will make it into a standard 2D polyline. Hope this may help!

ok thanks it made sense to me right now..

sometimes 2D drawings get out of shape too - and wind up with a z value

flatten sorts those out too

And any drawing that you receive from a civil engineer usually has elevated contour lines. So I typically Flatten a copy of their file to use as a base for my drawings.