quarter-disc is part of:

quarter-disc contains:

Full expansion for quarter-disc:
   100%  12x12 Quarter-Disc Brick
   100%  4x4 Quarter-Disc Brick
   100%  6x6 Quarter-Disc Plate
    10%  12x24 Sunken Dual-Quarter-Disc Brick
    10%  24x24 Brick Minus Quarter-Disc