Hi Mala,

re:
> Like you may see the crease is at the place where it belongs. But not outside and not rotated.
> How do I fix that?

You need to apply the rotation to the base object in relation to the base plane, not try to do it by rotating a trimmed area.

See these previous posts:
http://moi3d.com/forum/index.php?webtag=MOI&msg=10132.15
http://moi3d.com/forum/index.php?webtag=MOI&msg=10132.18

- Michael