I have a template for this block called the magic triangle by Sally Schneider Quilts. I have also found the directions for making it online. There is a book on the block also by the same teacher. I always had a problem with the 2 little triangles, not stretching them and making things go smoothly. You can certainly make this block without the template. The template is only used for squaring up the block.Here is a small demo of the idea.
http://www.sallyschneider.com/tools.html
and here is a version made without the template.
http://www.treadleon.net/quiltshop/T...eadleonia.html
And last a calculator to make the size that you want.
http://phoenixquiltguild.org/meeting...sTriangle.html
I used all of this information and my blocks came out perfect. I made the 6 inch blocks but the same concept would work on smaller ones.