Hope you don't mind if I add my 2 cents here Marilyn.
You can do both of these with HSTs. That is how I make them. Just use the right size template for the size quilt block you want to make.
I use my HST method to cut them out then sew them into a 4 x 4 grid.
http://www.quiltingboard.com/t-37915-1.htm
For a 12 1/2" quilt block of each use a 3 1/2" template to cut out your HSTs. Then just lay them out and sew them into rows and rows into the quilt block
If you want to make a differant size quilt block just change the size of template you use. Less math to confuse you.