Sew the four larger half squares together
to make the center pinwheel, using all scant 1/4" seam
allowances...
Then just piece the block, by
sewing the shorter small half square sets to the bock's center, then
adding the longer sets to the block's top and bottom. Press seams
towards the blocks center. All done! :o)
The quilt as shown
here will be 60" x 75"...one more block row across and
down would give you a generous Twin sized quilt!