Havplenty

there is so much information on cutting half square triangles and the math involved in them so it takes the guess work out of it for you. hopefully some of these links will work for you.

http://www.allpeoplequilt.com/techni...ngles_ss1.html
http://whipup.net/2011/03/17/guest-b...are-triangles/
http://www.blockcentral.com/a-halfsq...glepaper.shtml
http://www.quiltingboard.com/main-f1...t176908-3.html