I've added a parameter which shows the leg height of the transom or arched door way, it is currently not a user editable parameter but I will test it further and may make it user definable if that makes sense:
The arch leg height is defined or calculated by the following three parameters:
door width (w), transom/door height (h), arch radius (r )
and given by the following equation:
L = h - r(1-cos(asin(0.5*w/r)))
The arch leg height is defined or calculated by the following three parameters:
door width (w), transom/door height (h), arch radius (r )
and given by the following equation:
L = h - r(1-cos(asin(0.5*w/r)))