This is an interesting block. It is another square in a square, but both the center square (the on point square) and the corners of the outer square are pieced.
For this block, you will need:
- one 5 1/4″ sq of med light and dark fabric
- four 2 7/8″ sq of light and med dark fabric
When planning the approach to put this block together, I saw a couple of ways to choose from. Look at the block and I will point out the 2 different directions I contemplated. First focus on the on point square. It is made of of four units, each unit looks like four triangle points are coming together. These blocks are known as quarter square triangles. Now look at the four half square triangles within the center of the on point square – the pinwheel unit made up of four half square triangles. Next triangle units of med dark and light fabrics are on each side of the sq comprised of the four half sq triangle units configured in a pinwheel design. Next, larger triangles of dark and med light units are added to the newly formed square sides just as they would be if the center was made with four quarter square triangles. Have I lost you? It is okay if I did. As we sew the block together, you will see all the parts.
I chose to give directions for the second method described above. You will have more practice on making the triangle units that fit on the straight edges to build the block. Also, you will get more experience handling and sewing bias edges. A separate blog will be written on how to easily construct quarter sq triangles.
Steps for constructing this block begin with placing the two 5 1/4″ RST and cutting both diagonals. The purpose of cutting RST is to eliminate matching them later and possibly disturb the bias edges.
Lay the pieces as shown with the dark fabric on top. Note the 90 degree angle of the triangle is across the top and down the right side. Sew from the 90 degree corner down the side on the right. 
I chain piece (sew one set right after the other without cutting the thread) and then move the chain to the ironing board laying the chain out as it was sewn. Press the seams to relax the thread.
Now carefully open the triangle, pressing the seams to the lighter fabric. The photo shows 
to the darker fabric, but I had to repress to the lighter when sewing to the center unit. Thought I would save you a trip back to the iron! Snip them apart and cut off the dog ears. before you set them aside.
Follow the same process for 2 sets of 2 7/8″ squares except only cut one diagonal. Again, lay them out with the dark fabric on top, right angle (90 degree) across the top and down the right, and sew your seam. Press to the darker fabric and set aside.
Now with the four remaining 2 7/8″ squares, place RST light with med dark fabrics. We are making half square triangles, so draw a line corner to corner and one 1/4″ on each side of that line. You will sew one thread width away from the sewing lines toward the center cut line. Once sewn, you will have four half sq units. Carefully press the seam to the dark fabric. Place the four units together to form a pinwheel; sew the top row together, then the bottom row; press the seam to opposite sides; stitch the rows together nesting seams and press flat.
The smaller triangles previously sewn will now be sewn to the square sides. Lay the long side of the triangle unit on the pinwheel, RST, matching seams. Stitch. You will have a dog ear hanging off each side. You now attach the opposite side of the square with a triangle following the same procedure. Press open; trim dog ears; and, do the remaining two sides. Add the larger triangles in the same manner, press flat and you have completed Block 7! Not really difficult, just more pieces involved. Good work!