Word work crossword

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Across
  1. 3. The top of the house
  2. 4. What holds a building up?
  3. 6. A 2D shape converted to 3D in a very simple way
  4. 7. The design of an architecture on a blue paper
  5. 8. a 3D circle
  6. 9. Has a length, width, height and a volume
Down
  1. 1. If this is not stable, architecture will tumble down!
  2. 2. The material that hardens into a sidewalk
  3. 5. How much a container holds
  4. 6. You see these at Egypt, but it's also a 3D shape!