Related Clues:

• Expansion projects
• Pieces with 90-degree bends
• Building additions, sometimes
• Swell pair?
• Half-rectangle shapes
• Old yards
• Cloth measures
• Half-boxes
• Half-rectangles
• Right-angled additions
• Right-angled pipes
• Shelf-bracket shapes
• 90-degree angle formations
• Some Tetris pieces
• Additions, perhaps