Start with strips of red and background in two inch and 1.25 inch sizes. The two inch strips should be at least 12 inches long and the 1.25 inch strips should be at least 24 inches long. If you don't have scraps that long, feel free to use multiple short strips. This is a block that looks great scrappy.
Place the two inch strips right sides together and use the easy angle ruler to cut 8 HST units.
Now head to the sewing machine and sew the HST units together along the hypotenuse. At the same time, sew the 1.25 inch strips together as well.
Press the HST units and the strip set with the seams to the dark side. Sub cut the 1.25 inch strip set into 1.25 inch subunits. You will need 16 of these. Pair them together to make 8 four patches and sew.
Twirl the seams on your four patches and press them. Cute, right? Stack four of each unit together and arrange into a four patch as shown. Notice that the red squares make a nice straight line from the lower left to the upper right and the red triangles are all on the outside of the block. You are making 4 identical subunits that will be rotated to form the final block. Sew all four four patches together.
A quick look at the back:
When pressing the four patches, be sure to twirl your seams . Everything lines up perfectly and all the seams nestle nicely, but only if your seams are all twirled.
And now back to the front:
Here is your finished block. So striking in red and black.