One of the simplest arch trim pieces to measure.
The base measure is of the window (or window trim if present).
This is across the bottom of the arch.
To locate the base on arched windows that are over square windows,
mark where the arch starts with tape or a string to keep alignment.
And measure up the center from the same base mark.
And, of course, the depth the Half Round J Channel needs to be.
The depth is marked on the order as (D).
The width of the face (A) can be applied to the order form as well.
The flange on the rear will be 1 1/2" wider than the face to use as a nailer.
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