math vocabulary puzzle

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Across
  1. 3. symbol of a number unknown
  2. 4. surface where one side or end is higher than another
  3. 6. amount of terms between two lines with a common endpoint
  4. 8. property multiply the term in front of the parenthesis
  5. 9. capacity of an object
Down
  1. 1. the chance that something will happen
  2. 2. branch of math that substitutes letters for numbers
  3. 4. drawing drawing at a specific ratio relative to the actual size
  4. 5. math statement saying to things are equal
  5. 7. study of lines,rays,angles,points,surfaces