Been a long time since I was from around here, following several system
crashes and having to rebuild my hard drive from scratch, but I am again in
need of experience I don't have. Am building the Gambrel Shed/Garage out of
the Black & Decker Complete Guide to Sheds (second edition) and have hit a
speed-bump. P. 161 of that volume shows the template for the rafters, both
upper and lower, for that project, and I just don't understand the "lingo"
if you will, or the diagram by which the information for cutting these
rafters is given.

Somehow, I thought that I would be able to set my adjustable triangle to one
angle and be able to cut all the angles for said rafters. I realize I am
ignorant in this matter, but without actual notations as to what the
different angles are, and with the appearance that they are quite similar,
that just seemed natural. There is what appears to be a 30/60/90 triangle
for each of the upper and lower rafters, with different numbers on the
opposite and adjacent sides of each triangle, describing the roof slope for
each set of rafters. For the lower rafters, the triangle shows 24 inches
for the opposite side (I *think* I have this right) and 12 inches for the
adjacent side, indicating a steep slope. The reverse is true for the upper
rafters. It *looks* like I would set my triagle for something like 30
degrees and mark the seat and plumb cuts to make the upper angle, the Bird's
Mouth and the lower angle. 30 degrees won't give me the numbers shown in
the diagram for the length and depth of the Bird's Mouth, or the lowest
angle, however. 28 degrees will work for the Bird's Mouth, and 20 degrees
will work for the lower angle, but no one number will do both. Is this
normal, and the way things are done in this type of work? If someone will
tell me where to post the jpeg so I can list the link to it here, I will
gladly do this. I have't kept up very well with how things are done on the
Internet, and I have no idea as to where I could post the jpeg so those
reading this message may observe it.

Sorry to be so verbose, but I really need some help with this and am trying
to provide information on the problem as I see it. If there is a simple
answer to all of this, I do hope someone will take the time to enlighten me.

Thanks for reading this long post. Take it easy...

Dave