Using ¼" SA., stitch 2 sections of the star patches to within the ¼" SA of corners. (Called a floating seam). This will allow you to connect the corner and triangle sections.
Right sides together, match dots A and B in the square to dots A and B in the patch. (Note: both sides to connected star patches share a common dot.)
Stitch from dot to dot. Match dots A and C in the square to dots A and C in the patch.Stitch from dot to dot.

The same procedure is used for inserting triangles.

Even though I used star patches in this lesson, this procedure is used whenever a square or triangle patch has to be inserted into a block.