my best advice for this i would suggest is that you first;
1) Put it into top view. Select an object (piece of pie)
2) Move the view close to where you want it snapped to. Now with the move tool, hold v and mmb and snap to to where you want it.
If need be, press insert to change the pivot point and rotate it as and when you need to.
Hope this helps
those who succeed are only the failures that never gave up.
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