Related Clues:

• Something to build on?
• Restricted ___
• The 'A' of 38-Across
• See 65-Across
• Sphere of specialty
• Territory
• What a house may be built on
• Geometry topic
• Kind of rug or code
• Grounds
• Height times width
• Word with code or rug
• Side squared, for squares
• Carpentry calculation
• It's sometimes built on