The CONSTELLATION SERIES of rulers has been introduced with the Family Reunion Quilt and they are based on a Quarter Square Triangle so that the Quarter Square units can be mixed and matched with each other and with the Westalee Quarter Square Triangles.
By changing the cut of the strips to put the Bias on the outside of the blocks, the CONSTELLATION UNITS can be turned into Half Square Triangle units and mixed with Westalee Half Square Triangles increasing the number of blocks that can be made.

Set of 3 Templates with Fabric Guide