On 18 Dec 2005 17:45:47 -0800, "Pat" wrote:

I have to replace the moulding on a door. The door has two quarter
lites at the top, and these lites are curved. I am curious how to
calculate the angle that the mitre would need to be.

Any ideas? Is there a rule of thumb?

If you have the old trim pieces you can use them to find the angle.

If you have new trim pieces and don't have the old ones you can hold
the pieces on the door where they will be installed and make light
pencil marks to find your angle.
Hold one of the curved pieces up (where it will be installed) and put
a light mark on the wall and jamb along the top and bottom edge of the
piece approximately where the intersection will be. Then hold the
straight piece (where it will be installed) letting it overlap your
marks from the curved piece. Again, make a mark on both sides of the
straight piece where it intersects your first set of lines. The
intersections of your two lines will be the long and short points of
your angle. Hold your pieces up again and transfer your marks (at the
intersection) to your piece(s). Take the piece to your table saw or
miter saw and find your angle buy using the marks.
This will work for finding angles where curved pieces run into
straight pieces or where two pieces of different witdths need to
intersect.

Mike O.