Tarp shape question – Triangle vs rectangle

thats a diamond shape rather than triangle? you get the same efffect with a rotated rectangle or square. (Flying Diamond pitch). FD is the main pitch I use for the rae times I bivvy with a flat tarp.

A triangle would give a lot less length coverage unless huge (which brings other issues like weight and pitch ability into the mix). There is a reason they aren't obviously available.

Craig
The photo you linked to is of an 8'x8' (yes square) tarp set up as a diamond.
What appears to be a triangle is just a square tarp folded in half diagonally to give you two half square triangles.
Maybe this picture helps :

What I suggest you do is to take a look at this thread and follow that idea.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=33486
then google Tarp Shapes (or similar entry) and you will find pages with illustrations of this type :

once you have the size that works for you with the paper models get some painter's drop sheet (a few dollars at your hardware store) cut it to that size and make a full scale mock up so that you can see if it works or not for you.

Ah okay, thanks for explaining. I couldn't see the 4th corner… now I see it. Thanks for helping me catch up to the rest of the party.