Crown

Learn to cope with it.

You may want one of these to find the correct angles:

Now here's some sites to help:

Can't cope. I'm just a hack.

Sub contract it.

And make sure you have all your angles covered.

I would approach it by using two 1'-2' scraps of the molding, cut at 90 degrees at the each end. I would then take one scrap, select a corner and lightly scribe the left and right sides of the corner to locate the ceiling's intersecting line. I would then line up my left side and make my inside corner marks at the intersections and then my right. Cut it and see if I need to make any adjustments to the either the saw or table angle. I usually approach all instals of crown in this manner, whether 90 degree or not. Saves time and takes the guess work out of it. If you need further clarification I can email pics demonstrating how this is done. Herb

Assuming you mean the moulding has 8/12 pitch, not the walls...

I've been installing crown molding in my house. After installing molding in an eating area that had walls at 135 degree angles between them, I longed for those 90 degree walls. Coping at these angles is very tricky business. I had an easy time coping at 90. Pat myself on the back. When I got to this problem space I eventually gave up coping. The last of the joints here were simply mitered. My cieling in this area was also completely out of wack complicating the problem. Of course you may enjoy the challenge.

Good luck.