Thanks Arthur, Yes, your way of folding seems an easier way if you have a rectangular piece of fom to start with. Perhaps even easier if you have to fold the 3 lines of the bottom portion of the rectangle first. I'll have to look further at it.
Most of the exact steps I mentioned are shown with pictures on the site I referenced. http://chasm.merrimack.edu/~thull/geoconst.html > Neat stuff. > > You can have it a bit easier, though, even if not quite so general. Take > a rectangular piece of paper and lay it in front of you with one the the > short sides near you. Fold it in half from left to right (the long way) > and unfold it again. Now bring the lower left corner onto the crease from > the first fold, and crease a second fold through the lower right corner. > The second crease makes a 30 degree angle with the lower edge. > > Actually, I wasn't able to follow your instructions, Edley. I get line 6 > to be parallel to line 3 (45 degrees). I think there's a mistake, but I > haven't figured it out yet. > > --Art Carlson > > Dear Membership, > > Here is more help for Emergency Sundial Makers. > > Trigon - Folding > > When you need 15, 30, 45, 60, 75 degree angles to lay out radially > from a gnomon to create hour lines and don't even have a pencil, but > do have something foldable; paper, foil, starched linen, etc., here > is how to fold these angles. > > There turns out to be a number of ways to do this, but I'll describe > only one. > > It involves trisecting an angle. I found the method on > http://chasm.merrimack.edu/~thull/geoconst.html > > Starting from a scruffy piece of fom (foldable material) with no > straight lines in it's shape. > > A. Fold ... > >
