Making this block with Templates - most quilters these days don't choose templates for making simple blocks, but for those who do - here are templates for an 9 inch version of this Simple Pieces Block.
You can make this block using 4 templates for A, B, C and D.
Or you can use the templates for B and C, but rotary cut the triangles used for A and D to save some time.
Below shows the block and the sizes to cut the squares for A (3-7/8") and D (6-5/8"). Cutting each square in half diagonally will make two triangles for each corner to make two blocks.