Quick Piecing Half Square Triangles

On the second night of class, we learned a cool and quick way to make half square triangles (the ones we used in the Churn Dash).  Let's recap.


The Half Square Triangle


In our exercise, we started with 2 squares of fabric that were 4-7/8" X 4-7/8".  In this example, our squares are again 4-7/8" X 4-7/8" and one square will be green and one purple.  On the BACK of the green square, we draw a diagonal line from corner to corner.  We then place the two squares together, with the right sides of the fabrics "kissing."  This is how it should look (the purple fabric is behind the green):

Now, using our quater inch feet, we sew  lines that are 1/4" away from EACH side of the drawn line.  When we finish sewing the lines, it will look like this:

Now all we have left to do is cut on the DRAWN line, and we will have 2 half square triangles that look like this:

So, how do we know what size to cut our squares to begin with?

By looking at the block you want to make, figure out the "finished" size of your half square triangle.  The "finished" size is the size that the half square trianlge will be when it is sewn into your quilt.  In our Churn Dash, the finished size of the entire block is 12", and the finished size of the half square triangle is 4".
                                                  ====this half square triangle is 4" finished

  Now add 7/8", and you now know to cut your starting squares 4-7/8" X 4-7/8".  The math will always be the same---add 7/8" to your finished size half square triangles in order to make them the quick and easy way!