This block doesn’t have an official name in the Electric quilt or Block Base programs that I have. It’s simply called Mosaic #13.
Cutting Instructions:
Light Fabric: cut 8 squares @ 2 3/8 x 2 3/8 inches
Dark Fabric: cut 8 squares @ 2 3/8 x 2 3/8 inches
Assembly:
Draw a diagonal line on the wrong side of each of the light 2 3/8 inch squares. Pair these with the dark 2 3/8 inch squares, right sides together. Sew a 1/4 inch seam on each side of the drawn line. Cut apart on the drawn line and press to the dark.
Arrange your triangle squares as shown below and sew together.
Go here for finishing instructions. The large light triangles are on the outside of this one.