MATH

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Across
  1. 3. equation with unknown
  2. 4. right angle
  3. 6. less than 180 degrees, more than 90 degrees
  4. 8. multiply length * width
  5. 9. altogether
Down
  1. 1. addition of all sides
  2. 2. makes my life easier
  3. 5. operation we use to compare
  4. 7. 180 degrees